Realtime bandwidth-based communication for assistant systems

ABSTRACT

In one embodiment, a method includes initiating a communication session with a second client system associated with a second user via a communication network, wherein the communication session is initiated in a first modality, receiving a ping to the first client system from the communication network to evaluate available bandwidth on the communication network, estimating, by the first client system, an amount of bandwidth available on the communication network for use by the first client system, determining, by the first client system, the amount of bandwidth available on the communication network for use by the first client system is insufficient for the first modality, and switching the communication session with the second client system to a second modality by the first client system, wherein the second modality uses less bandwidth than the first modality.

PRIORITY

This application is a continuation under 35 U.S.C. § 120 of U.S. patent application Ser. No. 16/222,923, filed 17 Dec. 2018, which claims the benefit, under 35 U.S.C. § 119(e), of U.S. Provisional Patent Application No. 62/660,876, filed 20 Apr. 2018, which is incorporated herein by reference.

TECHNICAL FIELD

This disclosure generally relates to databases and file management within network environments, and in particular relates to hardware and software for smart assistant systems.

BACKGROUND

An assistant system can provide information or services on behalf of a user based on a combination of user input, location awareness, and the ability to access information from a variety of online sources (such as weather conditions, traffic congestion, news, stock prices, user schedules, retail prices, etc.). The user input may include text (e.g., online chat), especially in an instant messaging application or other applications, voice, images, motion, or a combination of them. The assistant system may perform concierge-type services (e.g., making dinner reservations, purchasing event tickets, making travel arrangements) or provide information based on the user input. The assistant system may also perform management or data-handling tasks based on online information and events without user initiation or interaction. Examples of those tasks that may be performed by an assistant system may include schedule management (e.g., sending an alert to a dinner date that a user is running late due to traffic conditions, update schedules for both parties, and change the restaurant reservation time). The assistant system may be enabled by the combination of computing devices, application programming interfaces (APIs), and the proliferation of applications on user devices.

A social-networking system, which may include a social-networking website, may enable its users (such as persons or organizations) to interact with it and with each other through it. The social-networking system may, with input from a user, create and store in the social-networking system a user profile associated with the user. The user profile may include demographic information, communication-channel information, and information on personal interests of the user. The social-networking system may also, with input from a user, create and store a record of relationships of the user with other users of the social-networking system, as well as provide services (e.g. profile/news feed posts, photo-sharing, event organization, messaging, games, or advertisements) to facilitate social interaction between or among users.

The social-networking system may send over one or more networks content or messages related to its services to a mobile or other computing device of a user. A user may also install software applications on a mobile or other computing device of the user for accessing a user profile of the user and other data within the social-networking system. The social-networking system may generate a personalized set of content objects to display to a user, such as a newsfeed of aggregated stories of other users connected to the user.

SUMMARY OF PARTICULAR EMBODIMENTS

In particular embodiments, the assistant system may assist a user to obtain information or services. The assistant system may enable the user to interact with it with multi-modal user input (such as voice, text, image, video, motion) in stateful and multi-turn conversations to get assistance. The assistant system may create and store a user profile comprising both personal and contextual information associated with the user. In particular embodiments, the assistant system may analyze the user input using natural-language understanding. The analysis may be based on the user profile for more personalized and context-aware understanding. The assistant system may resolve entities associated with the user input based on the analysis. In particular embodiments, the assistant system may interact with different agents to obtain information or services that are associated with the resolved entities. The assistant system may generate a response for the user regarding the information or services by using natural-language generation. Through the interaction with the user, the assistant system may use dialog management techniques to manage and forward the conversation flow with the user. In particular embodiments, the assistant system may further assist the user to effectively and efficiently digest the obtained information by summarizing the information. The assistant system may also assist the user to be more engaging with an online social network by providing tools that help the user interact with the online social network (e.g., creating posts, comments, messages). The assistant system may additionally assist the user to manage different tasks such as keeping track of events. In particular embodiments, the assistant system may proactively execute tasks that are relevant to user interests and preferences based on the user profile without a user input. In particular embodiments, the assistant system may check privacy settings to ensure that accessing a user's profile or other user information and executing different tasks are permitted subject to the user's privacy settings.

In particular embodiments, the content of Real-Time Communication (RTC) sessions such as Voice-over-Internet calls may be converted to content in a communication modality having a more compact format that uses less bandwidth. Voice calls may be converted to text using audio speech recognition, for example. The compact format may be sent via a communication network to a recipient device, which may convert the content in the compact modality back to the initial modality for presentation to a recipient user. For example, the recipient device may receive the text and convert it to audio using a technique such as text-to-speech. The resulting audio may then be played on a speaker of the recipient device. In this way, a reproduction of the content in the initial modality, e.g., speech, may be presented to the recipient user even if there is insufficient bandwidth to send the content in the initial modality. There may be differences between the initial and reproduced content, but the meaning of the reproduced content may be similar to or the same as the initial content. The compact modality may be any communication modality that can represent human-understandable communication using less data, and thus less network bandwidth, than the initial modality. For example, text may represent words of a natural language using less data than an audio recording of a person speaking the words, and the audio encoding may in turn use less data than a video recording of a person speaking the words. The voice or video calls may be made using, e.g., a messaging application or any other suitable voice/video communication service. Automated speech recognition and text-to-speech functionality may be provided by a smart assistant architecture or any other suitable system.

In particular embodiments, modality conversions may be to modalities that can represent fewer types of communication and use less bandwidth, or to modalities that can represent more types of communication and use more bandwidth. For example, in the conversion of audio to text, audio can directly represent words and sounds, while text can directly represent words but not sounds (though sounds can be represented indirectly as words in text). In this conversion, sounds from the audio that are not translated to text by automated speech recognition, such as intonations or other sounds, may be discarded, or may be added to the text as supplemental content, e.g., as a description of the sound. When the text is converted back to audio, the description in the text of the supplemental content may be used to generate the corresponding sound, which may be added to the speech generated by a text-to-speech technique. Video can represent gestures that are not directly representable in audio (or text). Conversion from video to audio (or text) may include discarding gesture content or adding supplemental audio (or text) content that describes the gestures to the generated audio (or text). Subsequently, when the audio (or text) is converted to video, the supplemental content may be converted back to gestures, e.g., by generating video animations of the gestures.

The embodiments disclosed herein are only examples, and the scope of this disclosure is not limited to them. Particular embodiments may include all, some, or none of the components, elements, features, functions, operations, or steps of the embodiments disclosed herein. Embodiments according to the invention are in particular disclosed in the attached claims directed to a method, a storage medium, a system and a computer program product, wherein any feature mentioned in one claim category, e.g. method, can be claimed in another claim category, e.g. system, as well. The dependencies or references back in the attached claims are chosen for formal reasons only. However any subject matter resulting from a deliberate reference back to any previous claims (in particular multiple dependencies) can be claimed as well, so that any combination of claims and the features thereof are disclosed and can be claimed regardless of the dependencies chosen in the attached claims. The subject-matter which can be claimed comprises not only the combinations of features as set out in the attached claims but also any other combination of features in the claims, wherein each feature mentioned in the claims can be combined with any other feature or combination of other features in the claims. Furthermore, any of the embodiments and features described or depicted herein can be claimed in a separate claim and/or in any combination with any embodiment or feature described or depicted herein or with any of the features of the attached claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example network environment associated with an assistant system.

FIG. 2 illustrates an example architecture of the assistant system.

FIG. 3 illustrates an example diagram flow of responding to a user request by the assistant system.

FIG. 4 illustrates an example network environment having links of different bandwidths.

FIG. 5 illustrates an example network environment in which client systems convert content between modalities for communication.

FIG. 6 illustrates an example network environment in which client systems convert speech to and from text for communication.

FIG. 7 illustrates a server that converts content between modalities.

FIGS. 8 and 9 illustrate example network environments in which client systems convert speech to and from text for communication associated with an assistant system.

FIG. 10 illustrates example conversions between content of different communication types associated with different modalities.

FIG. 11 illustrates an example method for communication by converting between different modalities.

FIG. 12 illustrates an example social graph.

FIG. 13 illustrates an example view of an embedding space.

FIG. 14 illustrates an example artificial neural network.

FIG. 15 illustrates an example computer system.

DESCRIPTION OF EXAMPLE EMBODIMENTS

System Overview

FIG. 1 illustrates an example network environment 100 associated with an assistant system. Network environment 100 includes a client system 130, an assistant system 140, a social-networking system 160, and a third-party system 170 connected to each other by a network 110. Although FIG. 1 illustrates a particular arrangement of a client system 130, an assistant system 140, a social-networking system 160, a third-party system 170, and a network 110, this disclosure contemplates any suitable arrangement of a client system 130, an assistant system 140, a social-networking system 160, a third-party system 170, and a network 110. As an example and not by way of limitation, two or more of a client system 130, a social-networking system 160, an assistant system 140, and a third-party system 170 may be connected to each other directly, bypassing a network 110. As another example, two or more of a client system 130, an assistant system 140, a social-networking system 160, and a third-party system 170 may be physically or logically co-located with each other in whole or in part. Moreover, although FIG. 1 illustrates a particular number of client systems 130, assistant systems 140, social-networking systems 160, third-party systems 170, and networks 110, this disclosure contemplates any suitable number of client systems 130, assistant systems 140, social-networking systems 160, third-party systems 170, and networks 110. As an example and not by way of limitation, network environment 100 may include multiple client systems 130, assistant systems 140, social-networking systems 160, third-party systems 170, and networks 110.

This disclosure contemplates any suitable network 110. As an example and not by way of limitation, one or more portions of a network 110 may include an ad hoc network, an intranet, an extranet, a virtual private network (VPN), a local area network (LAN), a wireless LAN (WLAN), a wide area network (WAN), a wireless WAN (WWAN), a metropolitan area network (MAN), a portion of the Internet, a portion of the Public Switched Telephone Network (PSTN), a cellular telephone network, or a combination of two or more of these. A network 110 may include one or more networks 110.

Links 150 may connect a client system 130, an assistant system 140, a social-networking system 160, and a third-party system 170 to a communication network 110 or to each other. This disclosure contemplates any suitable links 150. In particular embodiments, one or more links 150 include one or more wireline (such as for example Digital Subscriber Line (DSL) or Data Over Cable Service Interface Specification (DOCSIS)), wireless (such as for example Wi-Fi or Worldwide Interoperability for Microwave Access (WiMAX)), or optical (such as for example Synchronous Optical Network (SONET) or Synchronous Digital Hierarchy (SDH)) links. In particular embodiments, one or more links 150 each include an ad hoc network, an intranet, an extranet, a VPN, a LAN, a WLAN, a WAN, a WWAN, a MAN, a portion of the Internet, a portion of the PSTN, a cellular technology-based network, a satellite communications technology-based network, another link 150, or a combination of two or more such links 150. Links 150 need not necessarily be the same throughout a network environment 100. One or more first links 150 may differ in one or more respects from one or more second links 150.

In particular embodiments, a client system 130 may be an electronic device including hardware, software, or embedded logic components or a combination of two or more such components and capable of carrying out the appropriate functionalities implemented or supported by a client system 130. As an example and not by way of limitation, a client system 130 may include a computer system such as a desktop computer, notebook or laptop computer, netbook, a tablet computer, e-book reader, GPS device, camera, personal digital assistant (PDA), handheld electronic device, cellular telephone, smartphone, smart speaker, virtual reality (VR) headset, augment reality (AR) smart glasses, other suitable electronic device, or any suitable combination thereof. In particular embodiments, the client system 130 may be a smart assistant device. More information on smart assistant devices may be found in U.S. patent application Ser. No. 15/949,011, filed 9 Apr. 2018, U.S. Patent Application No. 62/655,751, filed 10 Apr. 2018, U.S. Design patent application No. 29/631910, filed 3 Jan. 2018, U.S. Design patent application No. 29/631747, filed 2 Jan. 2018, U.S. Design patent application No. 29/631913, filed 3 Jan. 2018, and U.S. Design patent application No. 29/631914, filed 3 Jan. 2018, each of which is incorporated by reference. This disclosure contemplates any suitable client systems 130. A client system 130 may enable a network user at a client system 130 to access a network 110. A client system 130 may enable its user to communicate with other users at other client systems 130.

In particular embodiments, a client system 130 may include a web browser 132, and may have one or more add-ons, plug-ins, or other extensions. A user at a client system 130 may enter a Uniform Resource Locator (URL) or other address directing a web browser 132 to a particular server (such as server 162, or a server associated with a third-party system 170), and the web browser 132 may generate a Hyper Text Transfer Protocol (HTTP) request and communicate the HTTP request to server. The server may accept the HTTP request and communicate to a client system 130 one or more Hyper Text Markup Language (HTML) files responsive to the HTTP request. The client system 130 may render a web interface (e.g. a webpage) based on the HTML files from the server for presentation to the user. This disclosure contemplates any suitable source files. As an example and not by way of limitation, a web interface may be rendered from HTML files, Extensible Hyper Text Markup Language (XHTML) files, or Extensible Markup Language (XML) files, according to particular needs. Such interfaces may also execute scripts such as, combinations of markup language and scripts, and the like. Herein, reference to a web interface encompasses one or more corresponding source files (which a browser may use to render the web interface) and vice versa, where appropriate.

In particular embodiments, a client system 130 may include a social-networking application 134 installed on the client system 130. A user at a client system 130 may use the social-networking application 134 to access on online social network. The user at the client system 130 may use the social-networking application 134 to communicate with the user's social connections (e.g., friends, followers, followed accounts, contacts, etc.). The user at the client system 130 may also use the social-networking application 134 to interact with a plurality of content objects (e.g., posts, news articles, ephemeral content, etc.) on the online social network. As an example and not by way of limitation, the user may browse trending topics and breaking news using the social-networking application 134.

In particular embodiments, a client system 130 may include an assistant application 136. A user at a client system 130 may use the assistant application 136 to interact with the assistant system 140. In particular embodiments, the assistant application 136 may comprise a stand-alone application. In particular embodiments, the assistant application 136 may be integrated into the social-networking application 134 or another suitable application (e.g., a messaging application). In particular embodiments, the assistant application 136 may be also integrated into the client system 130, an assistant hardware device, or any other suitable hardware devices. In particular embodiments, the assistant application 136 may be accessed via the web browser 132. In particular embodiments, the user may provide input via different modalities. As an example and not by way of limitation, the modalities may include audio, text, image, video, motion, etc. The assistant application 136 may communicate the user input to the assistant system 140. Based on the user input, the assistant system 140 may generate responses. The assistant system 140 may send the generated responses to the assistant application 136. The assistant application 136 may then present the responses to the user at the client system 130. The presented responses may be based on different modalities such as audio, text, image, and video. As an example and not by way of limitation, the user may verbally ask the assistant application 136 about the traffic information (i.e., via an audio modality). The assistant application 136 may then communicate the request to the assistant system 140. The assistant system 140 may accordingly generate the result and send it back to the assistant application 136. The assistant application 136 may further present the result to the user in text.

In particular embodiments, an assistant system 140 may assist users to retrieve information from different sources. The assistant system 140 may also assist user to request services from different service providers. In particular embodiments, the assist system 140 may receive a user request for information or services via the assistant application 136 in the client system 130. The assist system 140 may use natural-language understanding to analyze the user request based on user's profile and other relevant information. The result of the analysis may comprise different entities associated with an online social network. The assistant system 140 may then retrieve information or request services associated with these entities. In particular embodiments, the assistant system 140 may interact with the social-networking system 160 and/or third-party system 170 when retrieving information or requesting services for the user. In particular embodiments, the assistant system 140 may generate a personalized communication content for the user using natural-language generating techniques. The personalized communication content may comprise, for example, the retrieved information or the status of the requested services. In particular embodiments, the assistant system 140 may enable the user to interact with it regarding the information or services in a stateful and multi-turn conversation by using dialog-management techniques. The functionality of the assistant system 140 is described in more detail in the discussion of FIG. 2 below.

In particular embodiments, the social-networking system 160 may be a network-addressable computing system that can host an online social network. The social-networking system 160 may generate, store, receive, and send social-networking data, such as, for example, user-profile data, concept-profile data, social-graph information, or other suitable data related to the online social network. The social-networking system 160 may be accessed by the other components of network environment 100 either directly or via a network 110. As an example and not by way of limitation, a client system 130 may access the social-networking system 160 using a web browser 132, or a native application associated with the social-networking system 160 (e.g., a mobile social-networking application, a messaging application, another suitable application, or any combination thereof) either directly or via a network 110. In particular embodiments, the social-networking system 160 may include one or more servers 162. Each server 162 may be a unitary server or a distributed server spanning multiple computers or multiple datacenters. Servers 162 may be of various types, such as, for example and without limitation, web server, news server, mail server, message server, advertising server, file server, application server, exchange server, database server, proxy server, another server suitable for performing functions or processes described herein, or any combination thereof. In particular embodiments, each server 162 may include hardware, software, or embedded logic components or a combination of two or more such components for carrying out the appropriate functionalities implemented or supported by server 162. In particular embodiments, the social-networking system 160 may include one or more data stores 164. Data stores 164 may be used to store various types of information. In particular embodiments, the information stored in data stores 164 may be organized according to specific data structures. In particular embodiments, each data store 164 may be a relational, columnar, correlation, or other suitable database. Although this disclosure describes or illustrates particular types of databases, this disclosure contemplates any suitable types of databases. Particular embodiments may provide interfaces that enable a client system 130, a social-networking system 160, or a third-party system 170 to manage, retrieve, modify, add, or delete, the information stored in data store 164.

In particular embodiments, the social-networking system 160 may store one or more social graphs in one or more data stores 164. In particular embodiments, a social graph may include multiple nodes—which may include multiple user nodes (each corresponding to a particular user) or multiple concept nodes (each corresponding to a particular concept)—and multiple edges connecting the nodes. The social-networking system 160 may provide users of the online social network the ability to communicate and interact with other users. In particular embodiments, users may join the online social network via the social-networking system 160 and then add connections (e.g., relationships) to a number of other users of the social-networking system 160 whom they want to be connected to. Herein, the term “friend” may refer to any other user of the social-networking system 160 with whom a user has formed a connection, association, or relationship via the social-networking system 160.

In particular embodiments, the social-networking system 160 may provide users with the ability to take actions on various types of items or objects, supported by the social-networking system 160. As an example and not by way of limitation, the items and objects may include groups or social networks to which users of the social-networking system 160 may belong, events or calendar entries in which a user might be interested, computer-based applications that a user may use, transactions that allow users to buy or sell items via the service, interactions with advertisements that a user may perform, or other suitable items or objects. A user may interact with anything that is capable of being represented in the social-networking system 160 or by an external system of a third-party system 170, which is separate from the social-networking system 160 and coupled to the social-networking system 160 via a network 110.

In particular embodiments, the social-networking system 160 may be capable of linking a variety of entities. As an example and not by way of limitation, the social-networking system 160 may enable users to interact with each other as well as receive content from third-party systems 170 or other entities, or to allow users to interact with these entities through an application programming interfaces (API) or other communication channels.

In particular embodiments, a third-party system 170 may include one or more types of servers, one or more data stores, one or more interfaces, including but not limited to APIs, one or more web services, one or more content sources, one or more networks, or any other suitable components, e.g., that servers may communicate with. A third-party system 170 may be operated by a different entity from an entity operating the social-networking system 160. In particular embodiments, however, the social-networking system 160 and third-party systems 170 may operate in conjunction with each other to provide social-networking services to users of the social-networking system 160 or third-party systems 170. In this sense, the social-networking system 160 may provide a platform, or backbone, which other systems, such as third-party systems 170, may use to provide social-networking services and functionality to users across the Internet.

In particular embodiments, a third-party system 170 may include a third-party content object provider. A third-party content object provider may include one or more sources of content objects, which may be communicated to a client system 130. As an example and not by way of limitation, content objects may include information regarding things or activities of interest to the user, such as, for example, movie show times, movie reviews, restaurant reviews, restaurant menus, product information and reviews, or other suitable information. As another example and not by way of limitation, content objects may include incentive content objects, such as coupons, discount tickets, gift certificates, or other suitable incentive objects.

In particular embodiments, the social-networking system 160 also includes user-generated content objects, which may enhance a user's interactions with the social-networking system 160. User-generated content may include anything a user can add, upload, send, or “post” to the social-networking system 160. As an example and not by way of limitation, a user communicates posts to the social-networking system 160 from a client system 130. Posts may include data such as status updates or other textual data, location information, photos, videos, links, music or other similar data or media. Content may also be added to the social-networking system 160 by a third-party through a “communication channel,” such as a newsfeed or stream.

In particular embodiments, the social-networking system 160 may include a variety of servers, sub-systems, programs, modules, logs, and data stores. In particular embodiments, the social-networking system 160 may include one or more of the following: a web server, action logger, API-request server, relevance-and-ranking engine, content-object classifier, notification controller, action log, third-party-content-object-exposure log, inference module, authorization/privacy server, search module, advertisement-targeting module, user-interface module, user-profile store, connection store, third-party content store, or location store. The social-networking system 160 may also include suitable components such as network interfaces, security mechanisms, load balancers, failover servers, management-and-network-operations consoles, other suitable components, or any suitable combination thereof. In particular embodiments, the social-networking system 160 may include one or more user-profile stores for storing user profiles. A user profile may include, for example, biographic information, demographic information, behavioral information, social information, or other types of descriptive information, such as work experience, educational history, hobbies or preferences, interests, affinities, or location. Interest information may include interests related to one or more categories. Categories may be general or specific. As an example and not by way of limitation, if a user “likes” an article about a brand of shoes the category may be the brand, or the general category of “shoes” or “clothing.” A connection store may be used for storing connection information about users. The connection information may indicate users who have similar or common work experience, group memberships, hobbies, educational history, or are in any way related or share common attributes. The connection information may also include user-defined connections between different users and content (both internal and external). A web server may be used for linking the social-networking system 160 to one or more client systems 130 or one or more third-party systems 170 via a network 110. The web server may include a mail server or other messaging functionality for receiving and routing messages between the social-networking system 160 and one or more client systems 130. An API-request server may allow a third-party system 170 to access information from the social-networking system 160 by calling one or more APIs. An action logger may be used to receive communications from a web server about a user's actions on or off the social-networking system 160. In conjunction with the action log, a third-party-content-object log may be maintained of user exposures to third-party-content objects. A notification controller may provide information regarding content objects to a client system 130. Information may be pushed to a client system 130 as notifications, or information may be pulled from a client system 130 responsive to a request received from a client system 130. Authorization servers may be used to enforce one or more privacy settings of the users of the social-networking system 160. A privacy setting of a user determines how particular information associated with a user can be shared. The authorization server may allow users to opt in to or opt out of having their actions logged by the social-networking system 160 or shared with other systems (e.g., a third-party system 170), such as, for example, by setting appropriate privacy settings. Third-party-content-object stores may be used to store content objects received from third parties, such as a third-party system 170. Location stores may be used for storing location information received from client systems 130 associated with users. Advertisement-pricing modules may combine social information, the current time, location information, or other suitable information to provide relevant advertisements, in the form of notifications, to a user.

Assistant Systems

FIG. 2 illustrates an example architecture of the assistant system 140. In particular embodiments, the assistant system 140 may assist a user to obtain information or services. The assistant system 140 may enable the user to interact with it with multi-modal user input (such as voice, text, image, video, motion) in stateful and multi-turn conversations to get assistance. The assistant system 140 may create and store a user profile comprising both personal and contextual information associated with the user. In particular embodiments, the assistant system 140 may analyze the user input using natural-language understanding. The analysis may be based on the user profile for more personalized and context-aware understanding. The assistant system 140 may resolve entities associated with the user input based on the analysis. In particular embodiments, the assistant system 140 may interact with different agents to obtain information or services that are associated with the resolved entities. The assistant system 140 may generate a response for the user regarding the information or services by using natural-language generation. Through the interaction with the user, the assistant system 140 may use dialog management techniques to manage and forward the conversation flow with the user. In particular embodiments, the assistant system 140 may further assist the user to effectively and efficiently digest the obtained information by summarizing the information. The assistant system 140 may also assist the user to be more engaging with an online social network by providing tools that help the user interact with the online social network (e.g., creating posts, comments, messages). The assistant system 140 may additionally assist the user to manage different tasks such as keeping track of events. In particular embodiments, the assistant system 140 may proactively execute pre-authorized tasks that are relevant to user interests and preferences based on the user profile, at a time relevant for the user, without a user input. In particular embodiments, the assistant system 140 may check privacy settings to ensure that accessing a user's profile or other user information and executing different tasks are permitted subject to the user's privacy settings. More information on assisting users subject to privacy settings may be found in U.S. Patent Application No. 62/675,090, filed 22 May 2018, which is incorporated by reference.

In particular embodiments, the assistant system 140 may receive a user input from the assistant application 136 in the client system 130 associated with the user. In particular embodiments, the user input may be a user generated input that is sent to the assistant system 140 in a single turn. If the user input is based on a text modality, the assistant system 140 may receive it at a messaging platform 205. If the user input is based on an audio modality (e.g., the user may speak to the assistant application 136 or send a video including speech to the assistant application 136), the assistant system 140 may process it using an audio speech recognition (ASR) module 210 to convert the user input into text. If the user input is based on an image or video modality, the assistant system 140 may process it using optical character recognition techniques within the messaging platform 205 to convert the user input into text. The output of the messaging platform 205 or the ASR module 210 may be received at an assistant xbot 215. More information on handling user input based on different modalities may be found in U.S. patent application Ser. No. 16/053,600, filed 2 Aug. 2018, which is incorporated by reference.

In particular embodiments, the assistant xbot 215 may be a type of chat bot. The assistant xbot 215 may comprise a programmable service channel, which may be a software code, logic, or routine that functions as a personal assistant to the user. The assistant xbot 215 may work as the user's portal to the assistant system 140. The assistant xbot 215 may therefore be considered as a type of conversational agent. In particular embodiments, the assistant xbot 215 may send the textual user input to a natural-language understanding (NLU) module 220 to interpret the user input. In particular embodiments, the NLU module 220 may get information from a user context engine 225 and a semantic information aggregator (SIA) 230 to accurately understand the user input. The user context engine 225 may store the user profile of the user. The user profile of the user may comprise user-profile data including demographic information, social information, and contextual information associated with the user. The user-profile data may also include user interests and preferences on a plurality of topics, aggregated through conversations on news feed, search logs, messaging platform 205, etc. The usage of a user profile may be protected behind a privacy check module 245 to ensure that a user's information can be used only for his/her benefit, and not shared with anyone else. More information on user profiles may be found in U.S. patent application Ser. No. 15/967,239, filed 30 Apr. 2018, which is incorporated by reference. The semantic information aggregator 230 may provide ontology data associated with a plurality of predefined domains, intents, and slots to the NLU module 220. In particular embodiments, a domain may denote a social context of interaction, e.g., education. An intent may be an element in a pre-defined taxonomy of semantic intentions, which may indicate a purpose of a user interacting with the assistant system 140. In particular embodiments, an intent may be an output of the NLU module 220 if the user input comprises a text/speech input. The NLU module 220 may classify the text/speech input into a member of the pre-defined taxonomy, e.g., for the input “Play Beethoven's 5th,” the NLU module 220 may classify the input as having the intent [IN:play_music]. In particular embodiments, a domain may be conceptually a namespace for a set of intents, e.g., music. A slot may be a named sub-string with the user input, representing a basic semantic entity. For example, a slot for “pizza” may be [SL:dish]. In particular embodiments, a set of valid or expected named slots may be conditioned on the classified intent. As an example and not by way of limitation, for [IN:play_music], a slot may be [SL:song_name]. The semantic information aggregator 230 may additionally extract information from a social graph, a knowledge graph, and a concept graph, and retrieve a user's profile from the user context engine 225. The semantic information aggregator 230 may further process information from these different sources by determining what information to aggregate, annotating n-grams of the user input, ranking the n-grams with confidence scores based on the aggregated information, formulating the ranked n-grams into features that can be used by the NLU module 220 for understanding the user input. More information on aggregating semantic information may be found in U.S. patent application Ser. No. 15/967,342, filed 30 Apr. 2018, which is incorporated by reference. Based on the output of the user context engine 225 and the semantic information aggregator 230, the NLU module 220 may identify a domain, an intent, and one or more slots from the user input in a personalized and context-aware manner. As an example and not by way of limitation, a user input may comprise “show me how to get to the coffee shop”. The NLU module 220 may identify the particular coffee shop that the user wants to go based on the user's personal information and the associated contextual information. In particular embodiments, the NLU module 220 may comprise a lexicon of language and a parser and grammar rules to partition sentences into an internal representation. The NLU module 220 may also comprise one or more programs that perform naive semantics or stochastic semantic analysis to the use of pragmatics to understand a user input. In particular embodiments, the parser may be based on a deep learning architecture comprising multiple long-short term memory (LSTM) networks. As an example and not by way of limitation, the parser may be based on a recurrent neural network grammar (RNNG) model, which is a type of recurrent and recursive LSTM algorithm. More information on natural-language understanding may be found in U.S. patent application Ser. No. 16/011,062, filed 18 Jun. 2018, U.S. patent application Ser. No. 16/025,317, filed 2 Jul. 2018, and U.S. patent application Ser. No. 16/038,120, filed 17 Jul. 2018, each of which is incorporated by reference.

In particular embodiments, the identified domain, intent, and one or more slots from the NLU module 220 may be sent to a dialog engine 235. In particular embodiments, the dialog engine 235 may manage the dialog state and flow of the conversation between the user and the assistant xbot 215. The dialog engine 235 may additionally store previous conversations between the user and the assistant xbot 215. In particular embodiments, the dialog engine 235 may communicate with an entity resolution module 240 to resolve entities associated with the one or more slots, which supports the dialog engine 235 to forward the flow of the conversation between the user and the assistant xbot 215. In particular embodiments, the entity resolution module 240 may access the social graph, the knowledge graph, and the concept graph when resolving the entities. Entities may include, for example, unique users or concepts, each of which may have a unique identifier (ID). As an example and not by way of limitation, the knowledge graph may comprise a plurality of entities. Each entity may comprise a single record associated with one or more attribute values. The particular record may be associated with a unique entity identifier. Each record may have diverse values for an attribute of the entity. Each attribute value may be associated with a confidence probability. A confidence probability for an attribute value represents a probability that the value is accurate for the given attribute. Each attribute value may be also associated with a semantic weight. A semantic weight for an attribute value may represent how the value semantically appropriate for the given attribute considering all the available information. For example, the knowledge graph may comprise an entity of a movie “The Martian” (2015), which includes information that has been extracted from multiple content sources (e.g., Facebook, Wikipedia, movie review sources, media databases, and entertainment content sources), and then deduped, resolved, and fused to generate the single unique record for the knowledge graph. The entity may be associated with a space attribute value which indicates the genre of the movie “The Martian” (2015). More information on the knowledge graph may be found in U.S. patent application Ser. No. 16/048,049, filed 27 Jul. 2018, and U.S. patent application Ser. No. 16/048,101, filed 27 Jul. 2018, each of which is incorporated by reference. The entity resolution module 240 may additionally request a user profile of the user associated with the user input from the user context engine 225. In particular embodiments, the entity resolution module 240 may communicate with a privacy check module 245 to guarantee that the resolving of the entities does not violate privacy policies. In particular embodiments, the privacy check module 245 may use an authorization/privacy server to enforce privacy policies. As an example and not by way of limitation, an entity to be resolved may be another user who specifies in his/her privacy settings that his/her identity should not be searchable on the online social network, and thus the entity resolution module 240 may not return that user's identifier in response to a request. Based on the information obtained from the social graph, knowledge graph, concept graph, and user profile, and subject to applicable privacy policies, the entity resolution module 240 may therefore accurately resolve the entities associated with the user input in a personalized and context-aware manner. In particular embodiments, each of the resolved entities may be associated with one or more identifiers hosted by the social-networking system 160. As an example and not by way of limitation, an identifier may comprise a unique user identifier (ID). In particular embodiments, each of the resolved entities may be also associated with a confidence score. More information on resolving entities may be found in U.S. patent application Ser. No. 16/048,049, filed 27 Jul. 2018, and U.S. patent application Ser. No. 16/048,072, filed 27 Jul. 2018, each of which is incorporated by reference.

In particular embodiments, the dialog engine 235 may communicate with different agents based on the identified intent and domain, and the resolved entities. In particular embodiments, an agent may be an implementation that serves as a broker across a plurality of content providers for one domain. A content provider may be an entity responsible for carrying out an action associated with an intent or completing a task associated with the intent. As an example and not by way of limitation, multiple device-specific implementations (e.g., real-time calls for a client system 130 or a messaging application on the client system 130) may be handled internally by a single agent. Alternatively, these device-specific implementations may be handled by multiple agents associated with multiple domains. In particular embodiments, the agents may comprise first-party agents 250 and third-party agents 255. In particular embodiments, first-party agents 250 may comprise internal agents that are accessible and controllable by the assistant system 140 (e.g. agents associated with services provided by the online social network). In particular embodiments, third-party agents 255 may comprise external agents that the assistant system 140 has no control over (e.g., music streams agents (Online Music App), ticket sales agent). The first-party agents 250 may be associated with first-party providers 260 that provide content objects and/or services hosted by the social-networking system 160. The third-party agents 255 may be associated with third-party providers 265 that provide content objects and/or services hosted by the third-party system 170.

In particular embodiments, the communication from the dialog engine 235 to the first-party agents 250 may comprise requesting particular content objects and/or services provided by the first-party providers 260. As a result, the first-party agents 250 may retrieve the requested content objects from the first-party providers 260 and/or execute tasks that command the first-party providers 260 to perform the requested services. In particular embodiments, the communication from the dialog engine 235 to the third-party agents 255 may comprise requesting particular content objects and/or services provided by the third-party providers 265. As a result, the third-party agents 255 may retrieve the requested content objects from the third-party providers 265 and/or execute tasks that command the third-party providers 265 to perform the requested services. The third-party agents 255 may access the privacy check module 245 to guarantee no privacy violations before interacting with the third-party providers 265. As an example and not by way of limitation, the user associated with the user input may specify in his/her privacy settings that his/her profile information is invisible to any third-party content providers. Therefore, when retrieving content objects associated with the user input from the third-party providers 265, the third-party agents 255 may complete the retrieval without revealing to the third-party providers 265 which user is requesting the content objects.

In particular embodiments, each of the first-party agents 250 or third-party agents 255 may be designated for a particular domain. As an example and not by way of limitation, the domain may comprise weather, transportation, music, etc. In particular embodiments, the assistant system 140 may use a plurality of agents collaboratively to respond to a user input. As an example and not by way of limitation, the user input may comprise “direct me to my next meeting.” The assistant system 140 may use a calendar agent to retrieve the location of the next meeting. The assistant system 140 may then use a navigation agent to direct the user to the next meeting.

In particular embodiments, each of the first-party agents 250 or third-party agents 255 may retrieve a user profile from the user context engine 225 to execute tasks in a personalized and context-aware manner. As an example and not by way of limitation, a user input may comprise “book me a ride to the airport.” A transportation agent may execute the task of booking the ride. The transportation agent may retrieve the user profile of the user from the user context engine 225 before booking the ride. For example, the user profile may indicate that the user prefers taxis, so the transportation agent may book a taxi for the user. As another example, the contextual information associated with the user profile may indicate that the user is in a hurry so the transportation agent may book a ride from a ride-sharing service for the user since it may be faster to get a car from a ride-sharing service than a taxi company. In particular embodiment, each of the first-party agents 250 or third-party agents 255 may take into account other factors when executing tasks. As an example and not by way of limitation, other factors may comprise price, rating, efficiency, partnerships with the online social network, etc.

In particular embodiments, the dialog engine 235 may communicate with a conversational understanding composer (CU composer) 270. The dialog engine 235 may send the requested content objects and/or the statuses of the requested services to the CU composer 270. In particular embodiments, the dialog engine 235 may send the requested content objects and/or the statuses of the requested services as a <k, c, u, d> tuple, in which k indicates a knowledge source, c indicates a communicative goal, u indicates a user model, and d indicates a discourse model. In particular embodiments, the CU composer 270 may comprise a natural-language generator (NLG) 271 and a user interface (UI) payload generator 272. The natural-language generator 271 may generate a communication content based on the output of the dialog engine 235. In particular embodiments, the NLG 271 may comprise a content determination component, a sentence planner, and a surface realization component. The content determination component may determine the communication content based on the knowledge source, communicative goal, and the user's expectations. As an example and not by way of limitation, the determining may be based on a description logic. The description logic may comprise, for example, three fundamental notions which are individuals (representing objects in the domain), concepts (describing sets of individuals), and roles (representing binary relations between individuals or concepts). The description logic may be characterized by a set of constructors that allow the natural-language generator 271 to build complex concepts/roles from atomic ones. In particular embodiments, the content determination component may perform the following tasks to determine the communication content. The first task may comprise a translation task, in which the input to the natural-language generator 271 may be translated to concepts. The second task may comprise a selection task, in which relevant concepts may be selected among those resulted from the translation task based on the user model. The third task may comprise a verification task, in which the coherence of the selected concepts may be verified. The fourth task may comprise an instantiation task, in which the verified concepts may be instantiated as an executable file that can be processed by the natural-language generator 271. The sentence planner may determine the organization of the communication content to make it human understandable. The surface realization component may determine specific words to use, the sequence of the sentences, and the style of the communication content. The UI payload generator 272 may determine a preferred modality of the communication content to be presented to the user. In particular embodiments, the CU composer 270 may communicate with the privacy check module 245 to make sure the generation of the communication content follows the privacy policies. In particular embodiments, the CU composer 270 may retrieve a user profile from the user context engine 225 when generating the communication content and determining the modality of the communication content. As a result, the communication content may be more natural, personalized, and context-aware for the user. As an example and not by way of limitation, the user profile may indicate that the user likes short sentences in conversations so the generated communication content may be based on short sentences. As another example and not by way of limitation, the contextual information associated with the user profile may indicated that the user is using a device that only outputs audio signals so the UI payload generator 272 may determine the modality of the communication content as audio. More information on natural-language generation may be found in U.S. patent application Ser. No. 15/967,279, filed 30 Apr. 2018, and U.S. patent application Ser. No. 15/966,455, filed 30 Apr. 2018, each of which is incorporated by reference.

In particular embodiments, the CU composer 270 may send the generated communication content to the assistant xbot 215. In particular embodiments, the assistant xbot 215 may send the communication content to the messaging platform 205. The messaging platform 205 may further send the communication content to the client system 130 via the assistant application 136. In alternative embodiments, the assistant xbot 215 may send the communication content to a text-to-speech (TTS) module 275. The TTS module 275 may convert the communication content to an audio clip. The TTS module 275 may further send the audio clip to the client system 130 via the assistant application 136.

In particular embodiments, the assistant xbot 215 may interact with a proactive inference layer 280 without receiving a user input. The proactive inference layer 280 may infer user interests and preferences based on the user profile that is retrieved from the user context engine 225. In particular embodiments, the proactive inference layer 280 may further communicate with proactive agents 285 regarding the inference. The proactive agents 285 may execute proactive tasks based on the inference. As an example and not by way of limitation, the proactive tasks may comprise sending content objects or providing services to the user. In particular embodiments, each proactive task may be associated with an agenda item. The agenda item may comprise a recurring item such as a daily digest. The agenda item may also comprise a one-time item. In particular embodiments, a proactive agent 285 may retrieve the user profile from the user context engine 225 when executing the proactive task. Therefore, the proactive agent 285 may execute the proactive task in a personalized and context-aware manner. As an example and not by way of limitation, the proactive inference layer may infer that the user likes the band Maroon 5 and the proactive agent 285 may generate a recommendation of Maroon 5's new song/album to the user.

In particular embodiments, the proactive agent 285 may generate candidate entities associated with the proactive task based on a user profile. The generation may be based on a straightforward backend query using deterministic filters to retrieve the candidate entities from a structured data store. The generation may be alternatively based on a machine-learning model that is trained based on the user profile, entity attributes, and relevance between users and entities. As an example and not by way of limitation, the machine-learning model may be based on support vector machines (SVM). As another example and not by way of limitation, the machine-learning model may be based on a regression model. As another example and not by way of limitation, the machine-learning model may be based on a deep convolutional neural network (DCNN). In particular embodiments, the proactive agent 285 may also rank the generated candidate entities based on the user profile and the content associated with the candidate entities. The ranking may be based on the similarities between a user's interests and the candidate entities. As an example and not by way of limitation, the assistant system 140 may generate a feature vector representing a user's interest and feature vectors representing the candidate entities. The assistant system 140 may then calculate similarity scores (e.g., based on cosine similarity) between the feature vector representing the user's interest and the feature vectors representing the candidate entities. The ranking may be alternatively based on a ranking model that is trained based on user feedback data.

In particular embodiments, the proactive task may comprise recommending the candidate entities to a user. The proactive agent 285 may schedule the recommendation, thereby associating a recommendation time with the recommended candidate entities. The recommended candidate entities may be also associated with a priority and an expiration time. In particular embodiments, the recommended candidate entities may be sent to a proactive scheduler. The proactive scheduler may determine an actual time to send the recommended candidate entities to the user based on the priority associated with the task and other relevant factors (e.g., clicks and impressions of the recommended candidate entities). In particular embodiments, the proactive scheduler may then send the recommended candidate entities with the determined actual time to an asynchronous tier. The asynchronous tier may temporarily store the recommended candidate entities as a job. In particular embodiments, the asynchronous tier may send the job to the dialog engine 235 at the determined actual time for execution. In alternative embodiments, the asynchronous tier may execute the job by sending it to other surfaces (e.g., other notification services associated with the social-networking system 160). In particular embodiments, the dialog engine 235 may identify the dialog intent, state, and history associated with the user. Based on the dialog intent, the dialog engine 235 may select some candidate entities among the recommended candidate entities to send to the client system 130. In particular embodiments, the dialog state and history may indicate if the user is engaged in an ongoing conversation with the assistant xbot 215. If the user is engaged in an ongoing conversation and the priority of the task of recommendation is low, the dialog engine 235 may communicate with the proactive scheduler to reschedule a time to send the selected candidate entities to the client system 130. If the user is engaged in an ongoing conversation and the priority of the task of recommendation is high, the dialog engine 235 may initiate a new dialog session with the user in which the selected candidate entities may be presented. As a result, the interruption of the ongoing conversation may be prevented. When it is determined that sending the selected candidate entities is not interruptive to the user, the dialog engine 235 may send the selected candidate entities to the CU composer 270 to generate a personalized and context-aware communication content comprising the selected candidate entities, subject to the user's privacy settings. In particular embodiments, the CU composer 270 may send the communication content to the assistant xbot 215 which may then send it to the client system 130 via the messaging platform 205 or the TTS module 275. More information on proactively assisting users may be found in U.S. patent application Ser. No. 15/967,193, filed 30 Apr. 2018, and U.S. patent application Ser. No. 16/036,827, filed 16 Jul. 2018, each of which is incorporated by reference.

In particular embodiments, the assistant xbot 215 may communicate with a proactive agent 285 in response to a user input. As an example and not by way of limitation, the user may ask the assistant xbot 215 to set up a reminder. The assistant xbot 215 may request a proactive agent 285 to set up such reminder and the proactive agent 285 may proactively execute the task of reminding the user at a later time.

In particular embodiments, the assistant system 140 may comprise a summarizer 290. The summarizer 290 may provide customized news feed summaries to a user. In particular embodiments, the summarizer 290 may comprise a plurality of meta agents. The plurality of meta agents may use the first-party agents 250, third-party agents 255, or proactive agents 285 to generated news feed summaries. In particular embodiments, the summarizer 290 may retrieve user interests and preferences from the proactive inference layer 280. The summarizer 290 may then retrieve entities associated with the user interests and preferences from the entity resolution module 240. The summarizer 290 may further retrieve a user profile from the user context engine 225. Based on the information from the proactive inference layer 280, the entity resolution module 240, and the user context engine 225, the summarizer 290 may generate personalized and context-aware summaries for the user. In particular embodiments, the summarizer 290 may send the summaries to the CU composer 270. The CU composer 270 may process the summaries and send the processing results to the assistant xbot 215. The assistant xbot 215 may then send the processed summaries to the client system 130 via the messaging platform 205 or the TTS module 275. More information on summarization may be found in U.S. patent application Ser. No. 15/967,290, filed 30 Apr. 2018, which is incorporated by reference.

FIG. 3 illustrates an example diagram flow of responding to a user request by the assistant system 140. In particular embodiments, the assistant xbot 215 may access a request manager 305 upon receiving the user request. The request manager 305 may comprise a context extractor 306 and a conversational understanding object generator (CU object generator) 307. The context extractor 306 may extract contextual information associated with the user request. The context extractor 306 may also update contextual information based on the assistant application 136 executing on the client system 130. As an example and not by way of limitation, the update of contextual information may comprise content items are displayed on the client system 130. As another example and not by way of limitation, the update of contextual information may comprise alarm is set on the client system 130. As another example and not by way of limitation, the update of contextual information may comprise a song is playing on the client system 130. The CU object generator 307 may generate particular content objects relevant to the user request. The content objects may comprise dialog-session data and features associated with the user request, which may be shared with all the modules of the assistant system 140. In particular embodiments, the request manager 305 may store the contextual information and the generated content objects in data store 310 which is a particular data store implemented in the assistant system 140.

In particular embodiments, the request manger 305 may send the generated content objects to the NLU module 220. The NLU module 220 may perform a plurality of steps to process the content objects. At step 221, the NLU module 220 may generate a whitelist for the content objects. In particular embodiments, the whitelist may comprise interpretation data matching the user request. At step 222, the NLU module 220 may perform a featurization based on the whitelist. At step 223, the NLU module 220 may perform domain classification/selection on user request based on the features resulted from the featurization to classify the user request into predefined domains. The domain classification/selection results may be further processed based on two related procedures. At step 224 a, the NLU module 220 may process the domain classification/selection result using an intent classifier. The intent classifier may determine the user's intent associated with the user request. In particular embodiments, there may be one intent classifier for each domain to determine the most possible intents in a given domain. As an example and not by way of limitation, the intent classifier may be based on a machine-learning model that may take the domain classification/selection result as input and calculate a probability of the input being associated with a particular predefined intent. At step 224 b, the NLU module may process the domain classification/selection result using a meta-intent classifier. The meta-intent classifier may determine categories that describe the user's intent. In particular embodiments, intents that are common to multiple domains may be processed by the meta-intent classifier. As an example and not by way of limitation, the meta-intent classifier may be based on a machine-learning model that may take the domain classification/selection result as input and calculate a probability of the input being associated with a particular predefined meta-intent. At step 225 a, the NLU module 220 may use a slot tagger to annotate one or more slots associated with the user request. In particular embodiments, the slot tagger may annotate the one or more slots for the n-grams of the user request. At step 225 b, the NLU module 220 may use a meta slot tagger to annotate one or more slots for the classification result from the meta-intent classifier. In particular embodiments, the meta slot tagger may tag generic slots such as references to items (e.g., the first), the type of slot, the value of the slot, etc. As an example and not by way of limitation, a user request may comprise “change 500 dollars in my account to Japanese yen.” The intent classifier may take the user request as input and formulate it into a vector. The intent classifier may then calculate probabilities of the user request being associated with different predefined intents based on a vector comparison between the vector representing the user request and the vectors representing different predefined intents. In a similar manner, the slot tagger may take the user request as input and formulate each word into a vector. The intent classifier may then calculate probabilities of each word being associated with different predefined slots based on a vector comparison between the vector representing the word and the vectors representing different predefined slots. The intent of the user may be classified as “changing money”. The slots of the user request may comprise “500”, “dollars”, “account”, and “Japanese yen”. The meta-intent of the user may be classified as “financial service”. The meta slot may comprise “finance”.

In particular embodiments, the NLU module 220 may improve the domain classification/selection of the content objects by extracting semantic information from the semantic information aggregator 230. In particular embodiments, the semantic information aggregator 230 may aggregate semantic information in the following way. The semantic information aggregator 230 may first retrieve information from the user context engine 225. In particular embodiments, the user context engine 225 may comprise offline aggregators 226 and an online inference service 227. The offline aggregators 226 may process a plurality of data associated with the user that are collected from a prior time window. As an example and not by way of limitation, the data may include news feed posts/comments, interactions with news feed posts/comments, Instagram posts/comments, search history, etc. that are collected from a prior 90-day window. The processing result may be stored in the user context engine 225 as part of the user profile. The online inference service 227 may analyze the conversational data associated with the user that are received by the assistant system 140 at a current time. The analysis result may be stored in the user context engine 225 also as part of the user profile. In particular embodiments, both the offline aggregators 226 and online inference service 227 may extract personalization features from the plurality of data. The extracted personalization features may be used by other modules of the assistant system 140 to better understand user input. In particular embodiments, the semantic information aggregator 230 may then process the retrieved information, i.e., a user profile, from the user context engine 225 in the following steps. At step 231, the semantic information aggregator 230 may process the retrieved information from the user context engine 225 based on natural-language processing (NLP). In particular embodiments, the semantic information aggregator 230 may tokenize text by text normalization, extract syntax features from text, and extract semantic features from text based on NLP. The semantic information aggregator 230 may additionally extract features from contextual information, which is accessed from dialog history between a user and the assistant system 140. The semantic information aggregator 230 may further conduct global word embedding, domain-specific embedding, and/or dynamic embedding based on the contextual information. At step 232, the processing result may be annotated with entities by an entity tagger. Based on the annotations, the semantic information aggregator 230 may generate dictionaries for the retrieved information at step 233. In particular embodiments, the dictionaries may comprise global dictionary features which can be updated dynamically offline. At step 234, the semantic information aggregator 230 may rank the entities tagged by the entity tagger. In particular embodiments, the semantic information aggregator 230 may communicate with different graphs 330 including social graph, knowledge graph, and concept graph to extract ontology data that is relevant to the retrieved information from the user context engine 225. In particular embodiments, the semantic information aggregator 230 may aggregate the user profile, the ranked entities, and the information from the graphs 330. The semantic information aggregator 230 may then send the aggregated information to the NLU module 220 to facilitate the domain classification/selection.

In particular embodiments, the output of the NLU module 220 may be sent to a co-reference module 315 to interpret references of the content objects associated with the user request. In particular embodiments, the co-reference module 315 may be used to identify an item to which the user request refers. The co-reference module 315 may comprise reference creation 316 and reference resolution 317. In particular embodiments, the reference creation 316 may create references for entities determined by the NLU module 220. The reference resolution 317 may resolve these references accurately. As an example and not by way of limitation, a user request may comprise “find me the nearest supermarket and direct me there”. The co-reference module 315 may interpret “there” as “the nearest supermarket”. In particular embodiments, the co-reference module 315 may access the user context engine 225 and the dialog engine 235 when necessary to interpret references with improved accuracy.

In particular embodiments, the identified domains, intents, meta-intents, slots, and meta slots, along with the resolved references may be sent to the entity resolution module 240 to resolve relevant entities. The entity resolution module 240 may execute generic and domain-specific entity resolution. In particular embodiments, the entity resolution module 240 may comprise domain entity resolution 241 and generic entity resolution 242. The domain entity resolution 241 may resolve the entities by categorizing the slots and meta slots into different domains. In particular embodiments, entities may be resolved based on the ontology data extracted from the graphs 330. The ontology data may comprise the structural relationship between different slots/meta-slots and domains. The ontology may also comprise information of how the slots/meta-slots may be grouped, related within a hierarchy where the higher level comprises the domain, and subdivided according to similarities and differences. The generic entity resolution 242 may resolve the entities by categorizing the slots and meta slots into different generic topics. In particular embodiments, the resolving may be also based on the ontology data extracted from the graphs 330. The ontology data may comprise the structural relationship between different slots/meta-slots and generic topics. The ontology may also comprise information of how the slots/meta-slots may be grouped, related within a hierarchy where the higher level comprises the topic, and subdivided according to similarities and differences. As an example and not by way of limitation, in response to the input of an inquiry of the advantages of an electric car, the generic entity resolution 242 may resolve an electric car as vehicle and the domain entity resolution 241 may resolve the electric car as electric cars.

In particular embodiments, the output of the entity resolution module 240 may be sent to the dialog engine 235 to forward the flow of the conversation with the user. The dialog engine 235 may comprise dialog intent resolution 236 and dialog state update/ranker 237. In particular embodiments, the dialog intent resolution 236 may resolve the user intent associated with the current dialog session based on dialog history between the user and the assistant system 140. The dialog intent resolution 236 may map intents determined by the NLU module 220 to different dialog intents. The dialog intent resolution 236 may further rank dialog intents based on signals from the NLU module 220, the entity resolution module 240, and dialog history between the user and the assistant system 140. In particular embodiments, the dialog state update/ranker 237 may update/rank the dialog state of the current dialog session. As an example and not by way of limitation, the dialog state update/ranker 237 may update the dialog state as “completed” if the dialog session is over. As another example and not by way of limitation, the dialog state update/ranker 237 may rank the dialog state based on a priority associated with it.

In particular embodiments, the dialog engine 235 may communicate with a task completion module 335 about the dialog intent and associated content objects. In particular embodiments, the task completion module 335 may rank different dialog hypotheses for different dialog intents. The task completion module 335 may comprise an action selection component 336. In particular embodiments, the dialog engine 235 may additionally check against dialog policies 320 regarding the dialog state. In particular embodiments, a dialog policy 320 may comprise a data structure that describes an execution plan of an action by an agent 340. An agent 340 may select among registered content providers to complete the action. The data structure may be constructed by the dialog engine 235 based on an intent and one or more slots associated with the intent. A dialog policy 320 may further comprise multiple goals related to each other through logical operators. In particular embodiments, a goal may be an outcome of a portion of the dialog policy and it may be constructed by the dialog engine 235. A goal may be represented by an identifier (e.g., string) with one or more named arguments, which parameterize the goal. As an example and not by way of limitation, a goal with its associated goal argument may be represented as {confirm_artist, args: {artist: “Madonna”}}. In particular embodiments, a dialog policy may be based on a tree-structured representation, in which goals are mapped to leaves of the tree. In particular embodiments, the dialog engine 235 may execute a dialog policy 320 to determine the next action to carry out. The dialog policies 320 may comprise generic policy 321 and domain specific policies 322, both of which may guide how to select the next system action based on the dialog state. In particular embodiments, the task completion module 335 may communicate with dialog policies 320 to obtain the guidance of the next system action. In particular embodiments, the action selection component 336 may therefore select an action based on the dialog intent, the associated content objects, and the guidance from dialog policies 320.

In particular embodiments, the output of the task completion module 335 may be sent to the CU composer 270. In alternative embodiments, the selected action may require one or more agents 340 to be involved. As a result, the task completion module 335 may inform the agents 340 about the selected action. Meanwhile, the dialog engine 235 may receive an instruction to update the dialog state. As an example and not by way of limitation, the update may comprise awaiting agents' response. In particular embodiments, the CU composer 270 may generate a communication content for the user using the NLG 271 based on the output of the task completion module 335. In particular embodiments, the NLG 271 may use different language models and/or language templates to generate natural language outputs. The generation of natural language outputs may be application specific. The generation of natural language outputs may be also personalized for each user. The CU composer 270 may also determine a modality of the generated communication content using the UI payload generator 272. Since the generated communication content may be considered as a response to the user request, the CU composer 270 may additionally rank the generated communication content using a response ranker 273. As an example and not by way of limitation, the ranking may indicate the priority of the response.

In particular embodiments, the output of the CU composer 270 may be sent to a response manager 325. The response manager 325 may perform different tasks including storing/updating the dialog state 326 retrieved from data store 310 and generating responses 327. In particular embodiments, the output of CU composer 270 may comprise one or more of natural-language strings, speech, actions with parameters, or rendered images or videos that can be displayed in a VR headset or AR smart glass. As a result, the response manager 325 may determine what tasks to perform based on the output of CU composer 270. In particular embodiments, the generated response and the communication content may be sent to the assistant xbot 215. In alternative embodiments, the output of the CU composer 270 may be additionally sent to the TTS module 275 if the determined modality of the communication content is audio. The speech generated by the TTS module 275 and the response generated by the response manager 325 may be then sent to the assistant xbot 215.

Realtime Bandwidth-Based Communication

In particular embodiments, the content of Real-Time Communication (RTC) sessions such as Voice-over-Internet calls may be converted to content in a communication modality having a more compact format that uses less bandwidth. Voice calls may be converted to text using audio speech recognition, for example. The compact format may be sent via a communication network to a recipient device, which may convert the content in the compact modality back to the initial modality for presentation to a recipient user. For example, the recipient device may receive the text and convert it to audio using a technique such as text-to-speech. The resulting audio may then be played on a speaker of the recipient device. In this way, a reproduction of the content in the initial modality, e.g., speech, may be presented to the recipient user even if there is insufficient bandwidth to send the content in the initial modality. There may be differences between the initial and reproduced content, but the meaning of the reproduced content may be similar to or the same as the initial content. The compact modality may be any communication modality that can represent human-understandable communication using less data, and thus less network bandwidth, than the initial modality. For example, text may represent words of a natural language using less data than an audio recording of a person speaking the words, and the audio encoding may in turn use less data than a video recording of a person speaking the words. The voice or video calls may be made using, e.g., a messaging application or any other suitable voice/video communication service. Automated speech recognition and text-to-speech functionality may be provided by a smart assistant architecture or any other suitable system.

In particular embodiments, modality conversions may be to modalities that can represent fewer types of communication and use less bandwidth, or to modalities that can represent more types of communication and use more bandwidth. For example, in the conversion of audio to text, audio can directly represent words and sounds, while text can directly represent words but not sounds (though sounds can be represented indirectly as words in text). In this conversion, sounds from the audio that are not translated to text by automated speech recognition, such as intonations or other sounds, may be discarded, or may be added to the text as supplemental content, e.g., as a description of the sound. When the text is converted back to audio, the description in the text of the supplemental content may be used to generate the corresponding sound, which may be added to the speech generated by a text-to-speech technique. Video can represent gestures that are not directly representable in audio (or text). Conversion from video to audio (or text) may include discarding gesture content or adding supplemental audio (or text) content that describes the gestures to the generated audio (or text). Subsequently, when the audio (or text) is converted to video, the supplemental content may be converted back to gestures, e.g., by generating video animations of the gestures.

FIG. 4 illustrates an example network environment having links of different bandwidths. One or more client systems 130 a-c may communicate with one or more client systems 430 a-c via network 110. Client systems 130 a-c may communicate with network 110 via respective links 150 a-c, and client systems 430 a-c may communicate with network 110 via respective links 450 a-c. Links 150 a and 450 a are of a first type having a first available bandwidth, e.g., 10 Mbit/sec links. Links 150 b and 450 b are of a second type having a second available bandwidth, e.g., 100 Mbit/sec links. Links 150 c and 450 c are of a third type having a third available bandwidth, e.g., 1 Gbit/sec links. Client system 130 a may communicate with client system 430 a via link 150 a, network 110, and link 450 a. As an example, the available bandwidth of network 110 may be 1 Gbit/sec. Thus, the available bandwidth between two client systems 130 may be limited to the bandwidth of the slowest of the links 150 a-c, 450 a-c between the two client systems 130. For example, the available bandwidth between client systems 130 a and 430 a may be 100 Mbit/sec. As another example, the available bandwidth between client systems 130 b and 430 c may be 100 Mbit/sec because the bandwidth of link 150 b is 100 Mb/sec. In another example, the available bandwidth between client systems 130 c and 430 c may be 1 Gbit/sec. The term “communication network” as used herein may refer to any combination of the network 110 and one or more of the links 150 a-c, 450 a-c.

FIG. 5 illustrates an example network environment in which client systems convert content between modalities for communication. Voice or video calls may be made between two people, referred to as a caller and a recipient. The caller may be a user of the first client system 130 and the recipient may be a user of the second client system 430. The sound quality of such calls may be influenced by the bandwidth (e.g., cellular, WIFI, and so on) of the underlying network 110 and links 150. Voice or video calls ordinarily encode a caller's voice as audio data on the caller's client system 130 and send the audio data via the network 110 to a recipient's client system 430. If network bandwidth is sufficient for the voice calling protocol being used, e.g., Voice-Over-IP (VOIP), then the call may proceed using that protocol. However, problems with the network 110 can result in parts of the audio data not being received by the recipient's device, or being received too late. Thus, when a voice call's network connection quality is poor, portions of the conversation may be difficult for the recipient to understand. Particular embodiments may detect low-bandwidth connections during a voice call, use automated speech recognition to convert the caller's speech to text, and send the text to the recipient's device via the communication network 110 (instead of sending the audio data). The recipient's client system 430 may then use text-to-speech to generate audio from the text, and play the audio to the call recipient on the client system 430's speaker. Since text is significantly smaller in size than audio data, the text is more likely to be received intact by the recipient's client system 430 when network bandwidth is low. Although the recipient hears a computer-synthesized voice instead of the caller's voice, the communication remains in the same voice modality instead of switching to a different modality, such as text messaging, in which the caller and recipient would have to switch to typing instead of speaking. The recipient's client system 430 need not perform conversion back to the original modality. Instead, the received communication may be presented to the user in the same modality in which it is received. For example, the recipient's client system 430 may perform text-to-speech if the client system 430 is capable of text-to-speech. If the client system 430 is not capable of performing text-to-speech, then the client system 430 may display the received text displayed as a text message.

Referring to FIG. 5, a first client system 130 may communicate with a second client system 432 via links 150 and network 110. Each client system 130, 430 includes input devices 412 for receiving multi-modal user input (such as voice, text, image, video) from a user, and output devices 477 for presenting multi-modal output to a user. Each client system 130, 430 may also include an encoder 410 and a decoder 475, each of which may convert content from a modality such as voice, text, image, video to a different modality. Encoder 410 may convert user input to produce content in a different modality to be sent via network 110 to another client system 430. For example, voice input received via a microphone input device 412 may be converted to text by the encoder 410. Encoder 410 may be, e.g., an audio speech recognition module similar to ASR module 210. The content produced by encoder 410 may be sent via the network 110 from the first client system 130 to the second client system 430. The second client system 430 may receive the content and use decoder 475 to convert the received content to a different modality. Decoder 475 may be, e.g., a text-to-speech module similar to TTS module 275. The second client system 430 may present the decoded content, e.g., synthesized speech, to a user via output devices 477, e.g., a speaker.

Similarly to the communication from the first client system 130 to the second client system 430 described above, the second client system 430 may send content such as user input to the first client system 130 using encoder 410 to be decoded by the first client 130 using decoder 475. The second client system 430 may receive user input, e.g., voice, via input devices 412 and convert the user input to content another modality, e.g., text, using encoder 410. The content may be sent to the first client system 130 via network 110. The first client system 130 may receive the content and convert it to a different modality, e.g., text, using decoder 475. The first client system 130 may present the content in the different modality to a user using output devices 477. Although encoder 410 and decoder 475 are described as converting between specific modalities, encoder 410 and decoder 475 may convert between any suitable modalities. FIG. 6 is similar to FIG. 5, but shows ASR 210 as an example of encoder 410, and TTS 275 as an example of decoder 475.

In particular embodiments, network bandwidth may be divided into two or more categories. In a two-category example, bandwidth may be categorized as either good or bad (e.g., sufficient or too low). In this categorization, there are four possible cases for the bandwidth combinations: (1) Good/Good, in which both the caller and recipient have good network connectivity, (2) Bad/Bad, in which both the caller and the recipient have bad network connectivity, (3) Good/Bad or (4) Bad/Good, in which one has good connectivity and the other had bad connectivity. In particular embodiments, in the Good/Good case, the ordinarily communication mode (e.g., VOIP) may be used. In the Bad/Bad case, the call content may be converted to a modality that uses less bandwidth.

In particular embodiments, in the Good/Bad or Bad/Good case, in which one person has good connectivity and the other has bad connectivity, a determination may be made based on an evaluation of how good or bad the connectivity is. In these two cases, the call content may be converted to a modality that uses less bandwidth if, for example, the available bandwidth is insufficient for the ordinary communication mode. As an example, a more granular assessment of the connectivity may be made and compared to thresholds to determine whether to use the text mode. The implementation may depend on how frequently the network bandwidth can be evaluated. For example, if the bandwidth can be evaluated every 0.1 seconds, then checks may be performed frequently, and a decision as to whether to use the text mode may be made substantially in real-time by comparing the available bandwidth to a threshold bandwidth.

In particular embodiments, bandwidth evaluations may be aggregated over a period of time. For example, if out of the last 100 bandwidth evaluations (which may cover 10 seconds if they occur at 0.1 second intervals), the average rate is X, then a decision may be made adaptively, instead of potentially turning the text mode on or off every 0.1 seconds. Thus, a decision may be made for longer periods of time, so that larger chunks of conversation may be processed between switching modalities.

In particular embodiments, if the network bandwidth evaluations can only be performed once every few seconds (e.g., every 3, 5, or 10 seconds), then the text-mode decision may be based on the minimum bandwidth available during the last 10 second period. If there was a time during the last 10 second period where bandwidth was too low (e.g., below the minimum threshold), a switch to text mode may be made for the next 10 second period. The communication experience should be above a certain minimum level. That is, if the frequency of evaluating bandwidth is X seconds, the technique may look at the lowest bandwidth available in that X seconds. The lowest bandwidth thus corresponds to the frequency (e.g., every X seconds).

As another example, if the bandwidth evaluations are expected to have high overhead, then an initial bandwidth evaluation may be performed. If the initial evaluation finds that the bandwidth is good, then the frequency of future checks may be limited. The frequency of checking may be increased depending on a predicted likelihood of the quality being good. For example, if the device is in a location known to have low bandwidth (e.g., poor cellular reception), then the frequency of bandwidth evaluations may be increased, because an evaluation is more likely to detect low bandwidth.

In particular embodiments, bandwidth may be evaluated by checking for dropped packets during a call, or via other bandwidth-monitoring techniques. As another example, the client device may use its antenna strength as reported by the OS of the device to evaluate the bandwidth. The client device may report the antenna strength to the server, e.g., at a particular frequency, while the call is in progress. For example, the client may send a single bit to the server (e.g., with each packet) indicating whether the bandwidth is sufficiently good. As another example, the server may ping the client device to evaluate the bandwidth. In particular embodiments, if the caller passes through a tunnel or other area that interferes with network communication, then the caller's device may capture the voice, store it in a buffer, and, when the caller leaves the tunnel and communication is restored, send the buffered data in a text mode. Particular embodiments may provide an indication that the communication modality has switched, e.g., from the caller's real voice to a synthesized voice. The indication may be a beep, for example. Accessibility-related techniques may be used for representing sounds that are not translatable to text. For example, a caller who is singing “Happy Birthday” to the recipient may receive a visual indication that the singing is being translated to text. Similarly, the recipient may receive such a visual indication. Another indication may be a color change on the recipient's display.

In particular embodiments, voice personalization may be used by the caller's device to re-create the caller's voice. If the voice generated by the text-to-speech sounds sufficiently similar to the caller's voice, then the call may remain in the text modality (e.g., continue to convert speech to text) regardless of the bandwidth quality. The system may continue evaluating bandwidth while in the text mode. If the bandwidth meets a threshold for acceptable audio quality, then the system may switch to the audio mode and stop using the text mode for the conversation.

In particular embodiments, the modality switching techniques disclosed herein may benefit callers and receivers using network 110 by being less disruptive than the existing system behavior when bandwidth is low, such as intermittently choppy audio and dropped calls. Users making calls need not perform the bandwidth evaluation themselves. That is, users need not monitor a signal strength indicator or listen for low-quality audio. Instead, users simply initiate a voice call, and the system determines the available bandwidth and whether to switch to a different modality based on the available bandwidth.

In particular embodiments, network bandwidth may be divided into three categories. Example conversions for three different input modalities (text, audio, or video) and three bandwidth categories (low, medium, or high) to three output modalities are shown in TABLE 1 below. Low bandwidth may be, e.g., 1 Mbit/sec. Medium bandwidth may be, e.g., 10 Mbit/sec. High bandwidth may be, e.g., 100 Mbit/sec or 1 Gbit/sec.

TABLE 1 Output Modality Based on Available Bandwidth Input modality Low Medium High Video Convert to text Convert to audio No change Audio Convert to text No change No change, or “upgrade” on server to video/animation (e.g., if processing on server is preferred over processing on destination client system) Text No change No change, or “upgrade” No change, or “upgrade” on server to audio on server to video/animation (e.g., if processing on server (e.g., if processing on server is preferred over processing on is preferred over processing on destination client system) destination client system)

The conversions shown in TABLE 1 are merely examples. Although this disclosure describes performing particular conversions in a particular manner, this disclosure contemplates performing any suitable conversions in any suitable manner.

Particular embodiments may perform automatic translation between natural languages by translating the text and speaking the translation to the recipient. Although such translation may be performed for a phone call that uses network communication, a phone call is not necessary. The translation may be performed by a handheld or wearable device that acts as a translator box by receiving the user's speech in a first language, performs automated speech recognition to generate text from the speech, translates the text to a second language, and speaks the translated text. The second language may be a preset or detected language, such as a language detected based on the device's location. The device may perform real-time translation, or a close approximation thereof. The language preferences may be known to the clients and the server, e.g., that the caller prefers English and the recipient prefers Spanish. The clients may download language translation packages for particular languages as needed.

FIG. 7 illustrates a server 162 that converts content between modalities. In particular embodiments, the automated speech recognition (ASR) and text-to-speech (TTS) operations may be performed on the user's client systems 130, 430 (e.g., phones). There is a tradeoff between bandwidth and processing capacity. If a client system's available bandwidth is good or high, for example, then the server may perform the speech-related processing. If the available bandwidth is bad, low, or medium, for example, then the client system 130 may perform the speech-related processing. Depending on how much processing capacity the client system 130 has, and how much processing is needed for the speech-related processing, the client system 130 may or may not be suited for performing the automated speech recognition processing. If the device is not suited for the ASR processing, then the server 162 may perform it.

In particular embodiments, if there is sufficient bandwidth between a caller's client system 130 and a server 162, then the automated speech recognition may be performed on the server 162. Alternatively, if there is sufficient bandwidth between the server 162 and the recipient's client system 430, the text-to-speech may be performed on the server 162. Thus, the automated speech recognition or text-to-speech need not be performed on the client system of the user who has sufficient network bandwidth.

In particular embodiments, if sufficient bandwidth is available, content in a compact modality such as text may be converted to content in another modality such as audio that uses more storage space and thus more bandwidth than the first modality. This up-conversion may upgrade content to a modality that can represent more types of communication by generating animations such as avatars, emoji, facial expressions, or the like. The conversion may be performed on a server system or on the destination client system. Conversion on the server system may be desirable when the server has greater available processing capacity than the client system. Alternatively or additionally, text or audio may be sent to the destination client system 430 by the server and converted on the destination client system.

Referring to FIG. 7, the server 162 may include a decoder 475, which may perform conversion between modalities. The decoder 475 on server 162 may be used to perform modality conversion instead of a decoder 476 on the first client system 130 or the second client system 430. Further, the server 162 may include an encoder 410, which may be used to perform modality conversion instead of an encoder 410 on the first client system 130 or the second client system 430. The decoder 475 or encoder 410 may be used when, for example, conversion on the server 162 is more efficient than conversion on one or both of the client systems 130, 430, or when performing conversion on one or both of the client systems 130, 430 is not desirable, e.g., because of limited processing power available on one or both of the client systems 130, 430. Although this disclosure describes converting content between modalities in a particular manner, this disclosure contemplates converting content between modalities in any suitable manner.

FIGS. 8 and 9 illustrate example network environments in which client systems convert speech to and from text for communication associated with an assistant system. FIG. 8 is similar to FIG. 6, but shows ASR 210 and TTS 275 as modules that may communicate with client systems 130, 430 and with each other via network 110. The automated speech recognition and text-to-speech may be provided by the Assistant architecture. The Assistant system may utilize user profile information from (e.g., stored in a user context engine) to aid both in parsing speech via ASR (e.g., to more accurately parse spoken words to text) and generating synthesized speech via TTS (e.g., to generate synthetized speech that sounds more like the user).

Referring to FIG. 9, ASR 210 may communicate with TTS 275 via a messaging platform 205. The messaging platform 205 may send messages via a network 110 (not shown). The messages may contain content (such as voice, text, image, video), which may be converted to different modalities by modules such as ASR 210 and TTS 275. Although this disclosure describes using modules to convert between modalities in a particular manner, this disclosure contemplates using modules to convert between modalities in any suitable manner.

FIG. 10 illustrates example conversions between content of different communication types associated with different modalities. A table 1000 of size-reducing modality conversions lists three example modalities: video 1002, audio 1008, and text 1010. The conversions shown in table 1020 are to destination modalities that may use less data and can directly represent fewer types of communication than are directly representable in the source modality. Video 1002 can represent vocalizations 1004 and gestures 1006. Audio 1008 can represent vocalizations 1004. Text 1010 can represent words 1012. Vocalizations may be understood as an additional type of communication that can include intonations and other sounds not directly represented in words 1012.

A conversion from video 1002 to audio 1008 may involve conversion from a combination of vocalizations 1004 and gestures 1006 to vocalizations 1004. In this conversion, the gestures 1006 may be discarded, or an audio representation of the gestures may be generated and added to the generated audio 1008 as supplemental content, e.g., as an audio description of the gesture, such as “shrug” at the time in the generated audio 1008 that corresponds to a time in the video 1002 at which a person shrugs. The reverse conversion, conversion from audio 1008 to video 1002 may involve converting from vocalizations 1004 and supplemental content (if any) to a combination of vocalizations 1004 and gestures 1006. Gestures 1006 may be additional type of communication that can include non-verbal communication, e.g., facial expressions, body language, and so on, not directly representable in words 1012 or vocalizations 1004. If the audio includes the word “shrug” then an animation of a person shrugging maybe included in the generated video 1002 at a time in the video 1002 that corresponds to the time in the audio 1008 at which the word “shrug” occurs. The word “shrug” may have been included as supplemental content by the conversion from video 1002 to audio 1008 as described above. Alternatively or additionally, the word “shrug” may be spoken in the audio 1008 (without being added as supplemental content), and the audio to video conversion may still generate an animation of a person shrugging and include the animation in the generated video 1002 at the corresponding time.

A conversion from audio 1008 to text 1010 may involve conversion from vocalizations 1004 to words 1012. In this conversion, sounds from the audio that are not translated to text by automated speech recognition, such as intonations or other sounds, may be discarded, or may be added to the text as supplemental content, e.g., as a description of the sound, such as “hiccup.” When the text is converted back to audio, the description in the text of the supplemental content, e.g., “hiccup,” may be used to generate the corresponding sound, which may be added to the speech generated by a text-to-speech technique.

In particular embodiments, each modality in table 1000 is associated with one or more communication types. The communication types, which include vocalizations 1004, gestures 1006, and words 1012, may be understood as types of human communication that can be represented using the associated modalities. Vocalizations 1004 may correspond to spoken language or other sounds. Gestures 1006 may correspond to non-verbal communication, such as facial gestures, hand gestures, or other body gestures (e.g., shrugs). Words 1012 may correspond to text, e.g., written language. Video 1002 may be, e.g., video clips, and may represent vocalizations 1004 and gestures 1006. The vocalizations 1004 may be independent of or associated with the gestures 1006. In a particular communication, certain instances of vocalizations 1004 may have no associated instances of gestures 1006, and vice versa. A phrase may be spoken by a person without any accompanying gestures, and a gesture may be made without any accompanying speech. Other instances of vocalizations 1004 may have associated gestures 1006, e.g., spoken phrase may be accompanied by a simultaneous hand-waving gesture. Audio 1008 may be, e.g., audio clips of recorded speech, and may represent vocalizations 1004. Text 1010 may be a string of characters, e.g., “What time is it?”

In particular embodiments, video 1002 may be converted to audio 1008 by removing the gestures 1006 (and any other images) from the video 1002, or by copying the vocalizations 1004 but not the gestures 1005 from the video 1002. The amount of data needed to represent a particular communication as video may be greater than the amount of data needed to represent the communication as audio, since video images use a substantial quantity of data that is not needed for audio. Converting a particular communication from video to audio may result in loss of image content that is present in the video, such as video frames of gestures 1006, which may be removed by the conversion. Thus, conversion from a first modality to a second modality that uses less data may lose a portion of the meaning present in the content in the first modality. For example, the meaning of gestures 1006 that are present in the first modality may not be present in the second modality. To reduce the amount of meaning lost in the conversion, an additional conversion technique may be used. For example, gestures 1006 may be converted to vocalizations 1004 by automatically recognizing the gestures in the video 1002, generating additional vocalizations (e.g., synthesized speech) that describes the gestures, and including the additional vocalizations in the vocalizations 1004.

In particular embodiments, audio 1008 may be converted to text 1010 using ASR 210, for example. ASR 210 may generate words 1012 based on the vocalizations 1004. The amount of data needed to represent a particular communication as audio may be greater than the amount of data needed to represent the communication as text 1010, since audio uses a substantial quantity of data to represent vocalizations 1004 that is not needed to represent words 1012. Converting a particular communication from audio to text may result in loss of sound content that is present in the vocalizations 1004, such as intonations or other sounds, which may be removed by the conversion to words 1012 by ASR 210. As described above, conversion from a first modality to a second modality that uses less data may lose a portion of the meaning present in the content in the first modality. For example, the meaning of certain vocalizations 1006 that are present in the first modality, such as intonations or other sounds, may not be present in the second modality. To reduce the amount of meaning lost in the conversion, an additional conversion technique may be used. For example, intonations or other sounds may optionally be converted to words 1012, e.g., by automatically recognizing the intonations or other sounds, generating additional words that describes the intonations or other sounds, and including the additional words in the words 1012.

Although this disclosure describes converting from modalities having larger content sizes to modalities having smaller content sizes in a particular manner, this disclosure contemplates converting from modalities having larger content sizes to modalities having smaller content sizes in any suitable manner. As an example and not by way of limitation, video 1002 may be converted to text 1010 without an intermediate conversion to audio 1008, e.g., by using ASR 210 on the audio portion of the video 1002.

Referring again to FIG. 10, a table 1020 of size-increasing modality conversions lists three example modalities: text 1010, audio 1008, and video 1002. The conversions shown in table 1020 are to destination modalities that may use more data and can directly represent additional types of communication not directly representable in the source modality. A conversion from text 1010 to audio 1008 may involve converting from words 1012 to vocalizations 1004. A conversion from audio 1008 to video 1002 may involve converting from vocalizations 1004 to vocalizations 1004 (which may be the same as the vocalizations 1004 in the audio 1008) and gestures 1006.

Content for the additional type of communication may optionally be generated based on the content being converted using an additional conversion technique. Such generated content may be referred to herein as supplemental content. Types of communication that are not directly representable in a particular modality may be represented indirectly in that modality. The indirect representation may be converted to a direct representation or approximation in another modality. Text can represent or at least approximate vocalizations using words, such as “laugh” or “hiccup” that can be converted to vocalizations such as intonation or other sounds. Thus, vocalizations 1004 may be generated based on representations or approximations of vocalizations in words 1012, as shown by the dotted line from the words 1012 to the vocalizations 1004 in table 1020. Text can also represent or approximate gestures using certain words, such as “shrug” or “smile” that can be converted to the corresponding gestures. Vocalizations can also represent or approximate gestures using sounds such as the sound of laughter, which can be converted to corresponding facial expressions. Thus, gestures 1006 may be generated based on representations or approximations of gestures in vocalizations 1004 as shown by the dotted line from the vocalizations 1004 to the gestures 1006, or based on representations or approximations of gestures in words 1012 (not shown).

Text 1010 may be converted to audio 1008 using TTS 275, for example. TTS 275 may generate synthesized vocalizations 1004 based on the words 1012 of the text 1010. Audio can directly represent additional meaning using intonation and other sounds. Thus an additional conversion technique may be used to generate supplemental content for the modality that can represent an additional type of communication. Converting a particular communication from text to audio may thus include generating intonation and other sounds based on the text to include in the audio. For example, if a sentence of text ends in a question mark, the TTS 275 may increase the pitch of the synthesized words near the end of the sentence to mimic vocalization of a question.

In particular embodiments, audio 1008 may be converted to video 1002 by using the audio 1008 as an audio track in the video 1008 so that the vocalizations 1004 are included in the video. Optionally, supplemental content for gestures 1006, such as animations of facial gestures, may be automatically generated based on the vocalizations or on the words 1020 that are vocalized. The generated gestures 1006 may be included in the video 1002.

Although this disclosure describes converting to modalities having additional types of communication in a particular manner, this disclosure contemplates converting to modalities having additional types of communication in any suitable manner. As an example and not by way of limitation, text 1010 may be converted to video 1002 without an intermediate conversion to audio 1008, e.g., by using TTS 275 on the text 1010 to generate the audio portion of the video 1002, and optionally generating video, e.g., animations, based on the text 1010.

FIG. 11 illustrates an example method 1100 for communication by converting between different modalities. The method may begin at step 1110, where the assistant system 140 may receive, from a first client system associated with a first user during a communication session between the first client system and a second client system associated with a second user, a first user communication in a first modality, wherein the first user communication is to be sent via the communication network to the second client system. At step 1120, the assistant system 140 may determine an available bandwidth of the communication network with respect to the second client system. At step 1130, the assistant system 140 may determine a second modality to send the first user communication to the second client system, wherein the second modality is a suitable output modality determined based on the available bandwidth of the communication network with respect to the second client system, and wherein the first and second modalities are different modalities. At step 1140, the assistant system 140 may generate a second user communication in the second modality by converting the first user communication to the second modality. At step 1150, the assistant system 140 may send, to the second client system responsive to the first user communication, the second user communication for presentation to the second user. At step 1160, the assistant system 140 may receive, at the second client system, the second user communication. At step 1170, the assistant system 140 may generate, by the second client system a third user communication in the first modality by converting the second user communication to the first modality.

Particular embodiments may repeat one or more steps of the method of FIG. 11, where appropriate. Although this disclosure describes and illustrates particular steps of the method of FIG. 11 as occurring in a particular order, this disclosure contemplates any suitable steps of the method of FIG. 11 occurring in any suitable order. Moreover, although this disclosure describes and illustrates an example method for communication by converting between different modalities including the particular steps of the method of FIG. 11, this disclosure contemplates any suitable method for communication by converting between different modalities including any suitable steps, which may include all, some, or none of the steps of the method of FIG. 11, where appropriate. Furthermore, although this disclosure describes and illustrates particular components, devices, or systems carrying out particular steps of the method of FIG. 11, this disclosure contemplates any suitable combination of any suitable components, devices, or systems carrying out any suitable steps of the method of FIG. 11.

In particular embodiments, the assistant system 140 may receive, from a first client system associated with a first user during a communication session between the first client system and a second client system associated with a second user, a first user communication in a first modality, wherein the first user communication is to be sent via the communication network to the second client system. The first modality may be video, audio, text, an image, or the like. The first user communication comprises a video clip, an audio clip, a text string, or other suitable type of content.

In particular embodiments, the assistant system 140 may determine, by the one or more computing systems, an available bandwidth of the communication network with respect to the second client system. The one or more computing systems may include the first client system. For example, the first client system may perform at least one of the operations associated with the assistant system 140. As an example and not by way of limitation, the available bandwidth may be an estimate of an amount of bandwidth available on the communications network for use by the first client system. As an example and not by way of limitation, the communication session may be associated with a network interface that communicates with the communications network, and the available bandwidth is determined based on one or more attributes of the network interface. The attributes may include a network type or network bandwidth. The available bandwidth may be determined by sending a predetermined quantity of data via the communications network to a destination address, and measuring a rate at which the predetermined quantity of data is sent.

In particular embodiments, the assistant system 140 may determine, by the one or more computing systems, a second modality to send the first user communication to the second client system, wherein the second modality is a suitable output modality determined based on the available bandwidth of the communication network with respect to the second client system, and wherein the first and second modalities are different modalities.

In particular embodiments, the assistant system 140 may determine the second modality by determining whether the available bandwidth is sufficient to send the first user communication to the second client system in the first modality, and when the available bandwidth is determined to be insufficient to send the first user communication to the second client system in the first modality, determining the second modality such that the available bandwidth of the communication network is sufficient to send the second user communication in the second modality. As an example and not by way of limitation, the first modality may be video, and the available bandwidth maybe insufficient to send the first user communication as video, and (1) the second modality is audio when the available bandwidth is sufficient to send the first user communication as audio, or (b) the second modality is text when the available bandwidth is insufficient to send the first user communication as audio. The second modality may use more bandwidth than the first modality, and the available bandwidth of the communication network is sufficient to send the second user communication. As an example and not by way of limitation, the first modality may be text and the second modality may be audio, and converting the first user communication to the second modality may include converting the first user communication from text to audio-encoded speech, where the second user communication includes the audio-encoded speech. As an example and not by way of limitation, the first modality may be text and the second modality may be video, and converting the first user communication to the second modality may include converting the first user communication from text to video, the video including audio-encoded speech and animation based on the text, where the second user communication includes the video. The animation may include one or more avatars, emoji, or facial expressions based on the text.

As an example and not by way of limitation, the first modality may be audio and the second modality may be video, and converting the first user communication to the second modality may include converting the first user communication from audio to video including audio-encoded speech and animation based on the audio, where the second user communication includes the video.

In particular embodiments, the assistant system 140 may generate, by the one or more computing systems, a second user communication in the second modality by converting the first user communication to the second modality. In particular embodiments, the assistant system 140 may send, to the second client system responsive to the first user communication, the second user communication for presentation in the second modality to the second user.

In particular embodiments, the assistant system 140 may receive, at the second client system, the second user communication and generating, by the second client system a third user communication in the first modality by converting the second user communication to the first modality.

Social Graphs

FIG. 12 illustrates an example social graph 1200. In particular embodiments, the social-networking system 160 may store one or more social graphs 1200 in one or more data stores. In particular embodiments, the social graph 1200 may include multiple nodes—which may include multiple user nodes 1202 or multiple concept nodes 1204—and multiple edges 1206 connecting the nodes. Each node may be associated with a unique entity (i.e., user or concept), each of which may have a unique identifier (ID), such as a unique number or username. The example social graph 1200 illustrated in FIG. 12 is shown, for didactic purposes, in a two-dimensional visual map representation. In particular embodiments, a social-networking system 160, a client system 130, an assistant system 140, or a third-party system 170 may access the social graph 1200 and related social-graph information for suitable applications. The nodes and edges of the social graph 1200 may be stored as data objects, for example, in a data store (such as a social-graph database). Such a data store may include one or more searchable or queryable indexes of nodes or edges of the social graph 1200.

In particular embodiments, a user node 1202 may correspond to a user of the social-networking system 160 or the assistant system 140. As an example and not by way of limitation, a user may be an individual (human user), an entity (e.g., an enterprise, business, or third-party application), or a group (e.g., of individuals or entities) that interacts or communicates with or over the social-networking system 160 or the assistant system 140. In particular embodiments, when a user registers for an account with the social-networking system 160, the social-networking system 160 may create a user node 1202 corresponding to the user, and store the user node 1202 in one or more data stores. Users and user nodes 1202 described herein may, where appropriate, refer to registered users and user nodes 1202 associated with registered users. In addition or as an alternative, users and user nodes 1202 described herein may, where appropriate, refer to users that have not registered with the social-networking system 160. In particular embodiments, a user node 1202 may be associated with information provided by a user or information gathered by various systems, including the social-networking system 160. As an example and not by way of limitation, a user may provide his or her name, profile picture, contact information, birth date, sex, marital status, family status, employment, education background, preferences, interests, or other demographic information. In particular embodiments, a user node 1202 may be associated with one or more data objects corresponding to information associated with a user. In particular embodiments, a user node 1202 may correspond to one or more web interfaces.

In particular embodiments, a concept node 1204 may correspond to a concept. As an example and not by way of limitation, a concept may correspond to a place (such as, for example, a movie theater, restaurant, landmark, or city); a website (such as, for example, a website associated with the social-networking system 160 or a third-party website associated with a web-application server); an entity (such as, for example, a person, business, group, sports team, or celebrity); a resource (such as, for example, an audio file, video file, digital photo, text file, structured document, or application) which may be located within the social-networking system 160 or on an external server, such as a web-application server; real or intellectual property (such as, for example, a sculpture, painting, movie, game, song, idea, photograph, or written work); a game; an activity; an idea or theory; another suitable concept; or two or more such concepts. A concept node 1204 may be associated with information of a concept provided by a user or information gathered by various systems, including the social-networking system 160 and the assistant system 140. As an example and not by way of limitation, information of a concept may include a name or a title; one or more images (e.g., an image of the cover page of a book); a location (e.g., an address or a geographical location); a website (which may be associated with a URL); contact information (e.g., a phone number or an email address); other suitable concept information; or any suitable combination of such information. In particular embodiments, a concept node 1204 may be associated with one or more data objects corresponding to information associated with concept node 1204. In particular embodiments, a concept node 1204 may correspond to one or more web interfaces.

In particular embodiments, a node in the social graph 1200 may represent or be represented by a web interface (which may be referred to as a “profile interface”). Profile interfaces may be hosted by or accessible to the social-networking system 160 or the assistant system 1120. Profile interfaces may also be hosted on third-party websites associated with a third-party system 170. As an example and not by way of limitation, a profile interface corresponding to a particular external web interface may be the particular external web interface and the profile interface may correspond to a particular concept node 1204. Profile interfaces may be viewable by all or a selected subset of other users. As an example and not by way of limitation, a user node 1202 may have a corresponding user-profile interface in which the corresponding user may add content, make declarations, or otherwise express himself or herself. As another example and not by way of limitation, a concept node 1204 may have a corresponding concept-profile interface in which one or more users may add content, make declarations, or express themselves, particularly in relation to the concept corresponding to concept node 1204.

In particular embodiments, a concept node 1204 may represent a third-party web interface or resource hosted by a third-party system 170. The third-party web interface or resource may include, among other elements, content, a selectable or other icon, or other inter-actable object (which may be implemented, for example, in JavaScript, AJAX, or PHP codes) representing an action or activity. As an example and not by way of limitation, a third-party web interface may include a selectable icon such as “like,” “check-in,” “eat,” “recommend,” or another suitable action or activity. A user viewing the third-party web interface may perform an action by selecting one of the icons (e.g., “check-in”), causing a client system 130 to send to the social-networking system 160 a message indicating the user's action. In response to the message, the social-networking system 160 may create an edge (e.g., a check-in-type edge) between a user node 1202 corresponding to the user and a concept node 1204 corresponding to the third-party web interface or resource and store edge 1206 in one or more data stores.

In particular embodiments, a pair of nodes in the social graph 1200 may be connected to each other by one or more edges 1206. An edge 1206 connecting a pair of nodes may represent a relationship between the pair of nodes. In particular embodiments, an edge 1206 may include or represent one or more data objects or attributes corresponding to the relationship between a pair of nodes. As an example and not by way of limitation, a first user may indicate that a second user is a “friend” of the first user. In response to this indication, the social-networking system 160 may send a “friend request” to the second user. If the second user confirms the “friend request,” the social-networking system 160 may create an edge 1206 connecting the first user's user node 1202 to the second user's user node 1202 in the social graph 1200 and store edge 1206 as social-graph information in one or more of data stores 1612. In the example of FIG. 12, the social graph 1200 includes an edge 1206 indicating a friend relation between user nodes 1202 of user “A” and user “B” and an edge indicating a friend relation between user nodes 1202 of user “C” and user “B.” Although this disclosure describes or illustrates particular edges 1206 with particular attributes connecting particular user nodes 1202, this disclosure contemplates any suitable edges 1206 with any suitable attributes connecting user nodes 1202. As an example and not by way of limitation, an edge 1206 may represent a friendship, family relationship, business or employment relationship, fan relationship (including, e.g., liking, etc.), follower relationship, visitor relationship (including, e.g., accessing, viewing, checking-in, sharing, etc.), subscriber relationship, superior/subordinate relationship, reciprocal relationship, non-reciprocal relationship, another suitable type of relationship, or two or more such relationships. Moreover, although this disclosure generally describes nodes as being connected, this disclosure also describes users or concepts as being connected. Herein, references to users or concepts being connected may, where appropriate, refer to the nodes corresponding to those users or concepts being connected in the social graph 1200 by one or more edges 1206.

In particular embodiments, an edge 1206 between a user node 1202 and a concept node 1204 may represent a particular action or activity performed by a user associated with user node 1202 toward a concept associated with a concept node 1204. As an example and not by way of limitation, as illustrated in FIG. 12, a user may “like,” “attended,” “played,” “listened,” “cooked,” “worked at,” or “watched” a concept, each of which may correspond to an edge type or subtype. A concept-profile interface corresponding to a concept node 1204 may include, for example, a selectable “check in” icon (such as, for example, a clickable “check in” icon) or a selectable “add to favorites” icon. Similarly, after a user clicks these icons, the social-networking system 160 may create a “favorite” edge or a “check in” edge in response to a user's action corresponding to a respective action. As another example and not by way of limitation, a user (user “C”) may listen to a particular song (“Imagine”) using a particular application (Online Music App, which is an online music application). In this case, the social-networking system 160 may create a “listened” edge 1206 and a “used” edge (as illustrated in FIG. 12) between user nodes 1202 corresponding to the user and concept nodes 1204 corresponding to the song and application to indicate that the user listened to the song and used the application. Moreover, the social-networking system 160 may create a “played” edge 1206 (as illustrated in FIG. 12) between concept nodes 1204 corresponding to the song and the application to indicate that the particular song was played by the particular application. In this case, “played” edge 1206 corresponds to an action performed by an external application (Online Music App) on an external audio file (the song “Imagine”). Although this disclosure describes particular edges 1206 with particular attributes connecting user nodes 1202 and concept nodes 1204, this disclosure contemplates any suitable edges 1206 with any suitable attributes connecting user nodes 1202 and concept nodes 1204. Moreover, although this disclosure describes edges between a user node 1202 and a concept node 1204 representing a single relationship, this disclosure contemplates edges between a user node 1202 and a concept node 1204 representing one or more relationships. As an example and not by way of limitation, an edge 1206 may represent both that a user likes and has used at a particular concept. Alternatively, another edge 1206 may represent each type of relationship (or multiples of a single relationship) between a user node 1202 and a concept node 1204 (as illustrated in FIG. 12 between user node 1202 for user “E” and concept node 1204 for “Online Music App”).

In particular embodiments, the social-networking system 160 may create an edge 1206 between a user node 1202 and a concept node 1204 in the social graph 1200. As an example and not by way of limitation, a user viewing a concept-profile interface (such as, for example, by using a web browser or a special-purpose application hosted by the user's client system 130) may indicate that he or she likes the concept represented by the concept node 1204 by clicking or selecting a “Like” icon, which may cause the user's client system 130 to send to the social-networking system 160 a message indicating the user's liking of the concept associated with the concept-profile interface. In response to the message, the social-networking system 160 may create an edge 1206 between user node 1202 associated with the user and concept node 1204, as illustrated by “like” edge 1206 between the user and concept node 1204. In particular embodiments, the social-networking system 160 may store an edge 1206 in one or more data stores. In particular embodiments, an edge 1206 may be automatically formed by the social-networking system 160 in response to a particular user action. As an example and not by way of limitation, if a first user uploads a picture, watches a movie, or listens to a song, an edge 1206 may be formed between user node 1202 corresponding to the first user and concept nodes 1204 corresponding to those concepts. Although this disclosure describes forming particular edges 1206 in particular manners, this disclosure contemplates forming any suitable edges 1206 in any suitable manner.

Vector Spaces and Embeddings

FIG. 13 illustrates an example view of a vector space 1300. In particular embodiments, an object or an n-gram may be represented in a d-dimensional vector space, where d denotes any suitable number of dimensions. Although the vector space 1300 is illustrated as a three-dimensional space, this is for illustrative purposes only, as the vector space 1300 may be of any suitable dimension. In particular embodiments, an n-gram may be represented in the vector space 1300 as a vector referred to as a term embedding. Each vector may comprise coordinates corresponding to a particular point in the vector space 1300 (i.e., the terminal point of the vector). As an example and not by way of limitation, vectors 1310, 1320, and 1330 may be represented as points in the vector space 1300, as illustrated in FIG. 13. An n-gram may be mapped to a respective vector representation. As an example and not by way of limitation, n-grams t₁ and t₂ may be mapped to vectors

and

in the vector space 1300, respectively, by applying a function {right arrow over (π)} defined by a dictionary, such that

=

(t₁) and

=

(t₂). As another example and not by way of limitation, a dictionary trained to map text to a vector representation may be utilized, or such a dictionary may be itself generated via training. As another example and not by way of limitation, a model, such as Word2vec, may be used to map an n-gram to a vector representation in the vector space 1300. In particular embodiments, an n-gram may be mapped to a vector representation in the vector space 1300 by using a machine leaning model (e.g., a neural network). The machine learning model may have been trained using a sequence of training data (e.g., a corpus of objects each comprising n-grams).

In particular embodiments, an object may be represented in the vector space 1300 as a vector referred to as a feature vector or an object embedding. As an example and not by way of limitation, objects e₁ and e₂ may be mapped to vectors

and

in the vector space 1300, respectively, by applying a function

, such that

={right arrow over (π)}(e₁) and

=

(e₂). In particular embodiments, an object may be mapped to a vector based on one or more properties, attributes, or features of the object, relationships of the object with other objects, or any other suitable information associated with the object. As an example and not by way of limitation, a function may map objects to vectors by feature extraction, which may start from an initial set of measured data and build derived values (e.g., features). As an example and not by way of limitation, an object comprising a video or an image may be mapped to a vector by using an algorithm to detect or isolate various desired portions or shapes of the object. Features used to calculate the vector may be based on information obtained from edge detection, corner detection, blob detection, ridge detection, scale-invariant feature transformation, edge direction, changing intensity, autocorrelation, motion detection, optical flow, thresholding, blob extraction, template matching, Hough transformation (e.g., lines, circles, ellipses, arbitrary shapes), or any other suitable information. As another example and not by way of limitation, an object comprising audio data may be mapped to a vector based on features such as a spectral slope, a tonality coefficient, an audio spectrum centroid, an audio spectrum envelope, a Mel-frequency cepstrum, or any other suitable information. In particular embodiments, when an object has data that is either too large to be efficiently processed or comprises redundant data, a function {right arrow over (π)} may map the object to a vector using a transformed reduced set of features (e.g., feature selection). In particular embodiments, a function {right arrow over (π)} may map an object e to a vector

(e) based on one or more n-grams associated with object e. Although this disclosure describes representing an n-gram or an object in a vector space in a particular manner, this disclosure contemplates representing an n-gram or an object in a vector space in any suitable manner.

In particular embodiments, the social-networking system 160 may calculate a similarity metric of vectors in vector space 1300. A similarity metric may be a cosine similarity, a Minkowski distance, a Mahalanobis distance, a Jaccard similarity coefficient, or any suitable similarity metric. As an example and not by way of limitation, a similarity metric of

and

may be a cosine similarity

$\frac{\overset{\rightharpoonup}{v_{1}} \cdot \overset{\rightharpoonup}{v_{2}}}{{\overset{\rightharpoonup}{v_{1}}}\mspace{11mu} {\overset{\rightharpoonup}{v_{2}}}}.$

As another example and not by way of limitation, a similarity metric of

and

may be a Euclidean distance ∥

−

∥. A similarity metric of two vectors may represent how similar the two objects or n-grams corresponding to the two vectors, respectively, are to one another, as measured by the distance between the two vectors in the vector space 1300. As an example and not by way of limitation, vector 1310 and vector 1320 may correspond to objects that are more similar to one another than the objects corresponding to vector 1310 and vector 1330, based on the distance between the respective vectors. Although this disclosure describes calculating a similarity metric between vectors in a particular manner, this disclosure contemplates calculating a similarity metric between vectors in any suitable manner.

More information on vector spaces, embeddings, feature vectors, and similarity metrics may be found in U.S. patent application Ser. No. 14/949,436, filed 23 Nov. 2015, U.S. patent application Ser. No. 15/286,315, filed 5 Oct. 2016, and U.S. patent application Ser. No. 15/365,789, filed 30 Nov. 2016, each of which is incorporated by reference.

Artificial Neural Networks

FIG. 14 illustrates an example artificial neural network (“ANN”) 1400. In particular embodiments, an ANN may refer to a computational model comprising one or more nodes. Example ANN 1400 may comprise an input layer 1410, hidden layers 1420, 1430, 1460, and an output layer 1450. Each layer of the ANN 1400 may comprise one or more nodes, such as a node 1405 or a node 1415. In particular embodiments, each node of an ANN may be connected to another node of the ANN. As an example and not by way of limitation, each node of the input layer 1410 may be connected to one of more nodes of the hidden layer 1420. In particular embodiments, one or more nodes may be a bias node (e.g., a node in a layer that is not connected to and does not receive input from any node in a previous layer). In particular embodiments, each node in each layer may be connected to one or more nodes of a previous or subsequent layer. Although FIG. 14 depicts a particular ANN with a particular number of layers, a particular number of nodes, and particular connections between nodes, this disclosure contemplates any suitable ANN with any suitable number of layers, any suitable number of nodes, and any suitable connections between nodes. As an example and not by way of limitation, although FIG. 14 depicts a connection between each node of the input layer 1410 and each node of the hidden layer 1420, one or more nodes of the input layer 1410 may not be connected to one or more nodes of the hidden layer 1420.

In particular embodiments, an ANN may be a feedforward ANN (e.g., an ANN with no cycles or loops where communication between nodes flows in one direction beginning with the input layer and proceeding to successive layers). As an example and not by way of limitation, the input to each node of the hidden layer 1420 may comprise the output of one or more nodes of the input layer 1410. As another example and not by way of limitation, the input to each node of the output layer 1450 may comprise the output of one or more nodes of the hidden layer 1460. In particular embodiments, an ANN may be a deep neural network (e.g., a neural network comprising at least two hidden layers). In particular embodiments, an ANN may be a deep residual network. A deep residual network may be a feedforward ANN comprising hidden layers organized into residual blocks. The input into each residual block after the first residual block may be a function of the output of the previous residual block and the input of the previous residual block. As an example and not by way of limitation, the input into residual block N may be F(x)+x, where F(x) may be the output of residual block N−1, x may be the input into residual block N−1. Although this disclosure describes a particular ANN, this disclosure contemplates any suitable ANN.

In particular embodiments, an activation function may correspond to each node of an ANN. An activation function of a node may define the output of a node for a given input. In particular embodiments, an input to a node may comprise a set of inputs. As an example and not by way of limitation, an activation function may be an identity function, a binary step function, a logistic function, or any other suitable function. As another example and not by way of limitation, an activation function for a node k may be the sigmoid function

${{F_{k}\left( s_{k} \right)} = \frac{1}{1 + e^{- s_{k}}}},$

the hyperbolic tangent function

${{F_{k}\left( s_{k} \right)} = \frac{e^{s_{k}} - e^{- s_{k}}}{e^{s_{k}} + e^{- s_{k}}}},$

the rectifier F_(k) (s_(k))=max (0,s_(k)), or any other suitable function F_(k)(s_(k)), where s_(k) may be the effective input to node k. In particular embodiments, the input of an activation function corresponding to a node may be weighted. Each node may generate output using a corresponding activation function based on weighted inputs. In particular embodiments, each connection between nodes may be associated with a weight. As an example and not by way of limitation, a connection 1425 between the node 1405 and the node 1415 may have a weighting coefficient of 0.4, which may indicate that 0.4 multiplied by the output of the node 1405 is used as an input to the node 1415. As another example and not by way of limitation, the output y_(k) of node k may be y_(k)=F_(k) (S_(k)), where F_(k) may be the activation function corresponding to node k, s_(k)=Σ_(j)(w_(jk)x_(j)) may be the effective input to node k, x_(j) may be the output of a node j connected to node k, and w_(jk) may be the weighting coefficient between node j and node k. In particular embodiments, the input to nodes of the input layer may be based on a vector representing an object. Although this disclosure describes particular inputs to and outputs of nodes, this disclosure contemplates any suitable inputs to and outputs of nodes. Moreover, although this disclosure may describe particular connections and weights between nodes, this disclosure contemplates any suitable connections and weights between nodes.

In particular embodiments, an ANN may be trained using training data. As an example and not by way of limitation, training data may comprise inputs to the ANN 1400 and an expected output. As another example and not by way of limitation, training data may comprise vectors each representing a training object and an expected label for each training object. In particular embodiments, training an ANN may comprise modifying the weights associated with the connections between nodes of the ANN by optimizing an objective function. As an example and not by way of limitation, a training method may be used (e.g., the conjugate gradient method, the gradient descent method, the stochastic gradient descent) to backpropagate the sum-of-squares error measured as a distances between each vector representing a training object (e.g., using a cost function that minimizes the sum-of-squares error). In particular embodiments, an ANN may be trained using a dropout technique. As an example and not by way of limitation, one or more nodes may be temporarily omitted (e.g., receive no input and generate no output) while training. For each training object, one or more nodes of the ANN may have some probability of being omitted. The nodes that are omitted for a particular training object may be different than the nodes omitted for other training objects (e.g., the nodes may be temporarily omitted on an object-by-object basis). Although this disclosure describes training an ANN in a particular manner, this disclosure contemplates training an ANN in any suitable manner.

Privacy

In particular embodiments, one or more objects (e.g., content or other types of objects) of a computing system may be associated with one or more privacy settings. The one or more objects may be stored on or otherwise associated with any suitable computing system or application, such as, for example, a social-networking system 160, a client system 130, an assistant system 140, a third-party system 170, a social-networking application, an assistant application, a messaging application, a photo-sharing application, or any other suitable computing system or application. Although the examples discussed herein are in the context of an online social network, these privacy settings may be applied to any other suitable computing system. Privacy settings (or “access settings”) for an object may be stored in any suitable manner, such as, for example, in association with the object, in an index on an authorization server, in another suitable manner, or any suitable combination thereof. A privacy setting for an object may specify how the object (or particular information associated with the object) can be accessed, stored, or otherwise used (e.g., viewed, shared, modified, copied, executed, surfaced, or identified) within the online social network. When privacy settings for an object allow a particular user or other entity to access that object, the object may be described as being “visible” with respect to that user or other entity. As an example and not by way of limitation, a user of the online social network may specify privacy settings for a user-profile page that identify a set of users that may access work-experience information on the user-profile page, thus excluding other users from accessing that information.

In particular embodiments, privacy settings for an object may specify a “blocked list” of users or other entities that should not be allowed to access certain information associated with the object. In particular embodiments, the blocked list may include third-party entities. The blocked list may specify one or more users or entities for which an object is not visible. As an example and not by way of limitation, a user may specify a set of users who may not access photo albums associated with the user, thus excluding those users from accessing the photo albums (while also possibly allowing certain users not within the specified set of users to access the photo albums). In particular embodiments, privacy settings may be associated with particular social-graph elements. Privacy settings of a social-graph element, such as a node or an edge, may specify how the social-graph element, information associated with the social-graph element, or objects associated with the social-graph element can be accessed using the online social network. As an example and not by way of limitation, a particular concept node 1204 corresponding to a particular photo may have a privacy setting specifying that the photo may be accessed only by users tagged in the photo and friends of the users tagged in the photo. In particular embodiments, privacy settings may allow users to opt in to or opt out of having their content, information, or actions stored/logged by the social-networking system 160 or assistant system 140 or shared with other systems (e.g., a third-party system 170). Although this disclosure describes using particular privacy settings in a particular manner, this disclosure contemplates using any suitable privacy settings in any suitable manner.

In particular embodiments, privacy settings may be based on one or more nodes or edges of a social graph 1200. A privacy setting may be specified for one or more edges 1206 or edge-types of the social graph 1200, or with respect to one or more nodes 1202, 1204 or node-types of the social graph 1200. The privacy settings applied to a particular edge 1206 connecting two nodes may control whether the relationship between the two entities corresponding to the nodes is visible to other users of the online social network. Similarly, the privacy settings applied to a particular node may control whether the user or concept corresponding to the node is visible to other users of the online social network. As an example and not by way of limitation, a first user may share an object to the social-networking system 160. The object may be associated with a concept node 1204 connected to a user node 1202 of the first user by an edge 1206. The first user may specify privacy settings that apply to a particular edge 1206 connecting to the concept node 1204 of the object, or may specify privacy settings that apply to all edges 1206 connecting to the concept node 1204. As another example and not by way of limitation, the first user may share a set of objects of a particular object-type (e.g., a set of images). The first user may specify privacy settings with respect to all objects associated with the first user of that particular object-type as having a particular privacy setting (e.g., specifying that all images posted by the first user are visible only to friends of the first user and/or users tagged in the images).

In particular embodiments, the social-networking system 160 may present a “privacy wizard” (e.g., within a webpage, a module, one or more dialog boxes, or any other suitable interface) to the first user to assist the first user in specifying one or more privacy settings. The privacy wizard may display instructions, suitable privacy-related information, current privacy settings, one or more input fields for accepting one or more inputs from the first user specifying a change or confirmation of privacy settings, or any suitable combination thereof. In particular embodiments, the social-networking system 160 may offer a “dashboard” functionality to the first user that may display, to the first user, current privacy settings of the first user. The dashboard functionality may be displayed to the first user at any appropriate time (e.g., following an input from the first user summoning the dashboard functionality, following the occurrence of a particular event or trigger action). The dashboard functionality may allow the first user to modify one or more of the first user's current privacy settings at any time, in any suitable manner (e.g., redirecting the first user to the privacy wizard).

Privacy settings associated with an object may specify any suitable granularity of permitted access or denial of access. As an example and not by way of limitation, access or denial of access may be specified for particular users (e.g., only me, my roommates, my boss), users within a particular degree-of-separation (e.g., friends, friends-of-friends), user groups (e.g., the gaming club, my family), user networks (e.g., employees of particular employers, students or alumni of particular university), all users (“public”), no users (“private”), users of third-party systems 170, particular applications (e.g., third-party applications, external websites), other suitable entities, or any suitable combination thereof. Although this disclosure describes particular granularities of permitted access or denial of access, this disclosure contemplates any suitable granularities of permitted access or denial of access.

In particular embodiments, one or more servers 162 may be authorization/privacy servers for enforcing privacy settings. In response to a request from a user (or other entity) for a particular object stored in a data store 164, the social-networking system 160 may send a request to the data store 164 for the object. The request may identify the user associated with the request and the object may be sent only to the user (or a client system 130 of the user) if the authorization server determines that the user is authorized to access the object based on the privacy settings associated with the object. If the requesting user is not authorized to access the object, the authorization server may prevent the requested object from being retrieved from the data store 164 or may prevent the requested object from being sent to the user. In the search-query context, an object may be provided as a search result only if the querying user is authorized to access the object, e.g., if the privacy settings for the object allow it to be surfaced to, discovered by, or otherwise visible to the querying user. In particular embodiments, an object may represent content that is visible to a user through a newsfeed of the user. As an example and not by way of limitation, one or more objects may be visible to a user's “Trending” page. In particular embodiments, an object may correspond to a particular user. The object may be content associated with the particular user, or may be the particular user's account or information stored on the social-networking system 160, or other computing system. As an example and not by way of limitation, a first user may view one or more second users of an online social network through a “People You May Know” function of the online social network, or by viewing a list of friends of the first user. As an example and not by way of limitation, a first user may specify that they do not wish to see objects associated with a particular second user in their newsfeed or friends list. If the privacy settings for the object do not allow it to be surfaced to, discovered by, or visible to the user, the object may be excluded from the search results. Although this disclosure describes enforcing privacy settings in a particular manner, this disclosure contemplates enforcing privacy settings in any suitable manner.

In particular embodiments, different objects of the same type associated with a user may have different privacy settings. Different types of objects associated with a user may have different types of privacy settings. As an example and not by way of limitation, a first user may specify that the first user's status updates are public, but any images shared by the first user are visible only to the first user's friends on the online social network. As another example and not by way of limitation, a user may specify different privacy settings for different types of entities, such as individual users, friends-of-friends, followers, user groups, or corporate entities. As another example and not by way of limitation, a first user may specify a group of users that may view videos posted by the first user, while keeping the videos from being visible to the first user's employer. In particular embodiments, different privacy settings may be provided for different user groups or user demographics. As an example and not by way of limitation, a first user may specify that other users who attend the same university as the first user may view the first user's pictures, but that other users who are family members of the first user may not view those same pictures.

In particular embodiments, the social-networking system 160 may provide one or more default privacy settings for each object of a particular object-type. A privacy setting for an object that is set to a default may be changed by a user associated with that object. As an example and not by way of limitation, all images posted by a first user may have a default privacy setting of being visible only to friends of the first user and, for a particular image, the first user may change the privacy setting for the image to be visible to friends and friends-of-friends.

In particular embodiments, privacy settings may allow a first user to specify (e.g., by opting out, by not opting in) whether the social-networking system 160 or assistant system 140 may receive, collect, log, or store particular objects or information associated with the user for any purpose. In particular embodiments, privacy settings may allow the first user to specify whether particular applications or processes may access, store, or use particular objects or information associated with the user. The privacy settings may allow the first user to opt in or opt out of having objects or information accessed, stored, or used by specific applications or processes. The social-networking system 160 or assistant system 140 may access such information in order to provide a particular function or service to the first user, without the social-networking system 160 or assistant system 140 having access to that information for any other purposes. Before accessing, storing, or using such objects or information, the social-networking system 160 or assistant system 140 may prompt the user to provide privacy settings specifying which applications or processes, if any, may access, store, or use the object or information prior to allowing any such action. As an example and not by way of limitation, a first user may transmit a message to a second user via an application related to the online social network (e.g., a messaging app), and may specify privacy settings that such messages should not be stored by the social-networking system 160 or assistant system 140.

In particular embodiments, a user may specify whether particular types of objects or information associated with the first user may be accessed, stored, or used by the social-networking system 160 or assistant system 140. As an example and not by way of limitation, the first user may specify that images sent by the first user through the social-networking system 160 or assistant system 140 may not be stored by the social-networking system 160 or assistant system 140. As another example and not by way of limitation, a first user may specify that messages sent from the first user to a particular second user may not be stored by the social-networking system 160 or assistant system 140. As yet another example and not by way of limitation, a first user may specify that all objects sent via a particular application may be saved by the social-networking system 160 or assistant system 140.

In particular embodiments, privacy settings may allow a first user to specify whether particular objects or information associated with the first user may be accessed from particular client systems 130 or third-party systems 170. The privacy settings may allow the first user to opt in or opt out of having objects or information accessed from a particular device (e.g., the phone book on a user's smart phone), from a particular application (e.g., a messaging app), or from a particular system (e.g., an email server). The social-networking system 160 or assistant system 140 may provide default privacy settings with respect to each device, system, or application, and/or the first user may be prompted to specify a particular privacy setting for each context. As an example and not by way of limitation, the first user may utilize a location-services feature of the social-networking system 160 or assistant system 140 to provide recommendations for restaurants or other places in proximity to the user. The first user's default privacy settings may specify that the social-networking system 160 or assistant system 140 may use location information provided from a client device 130 of the first user to provide the location-based services, but that the social-networking system 160 or assistant system 140 may not store the location information of the first user or provide it to any third-party system 170. The first user may then update the privacy settings to allow location information to be used by a third-party image-sharing application in order to geo-tag photos.

In particular embodiments, privacy settings may allow a user to specify one or more geographic locations from which objects can be accessed. Access or denial of access to the objects may depend on the geographic location of a user who is attempting to access the objects. As an example and not by way of limitation, a user may share an object and specify that only users in the same city may access or view the object. As another example and not by way of limitation, a first user may share an object and specify that the object is visible to second users only while the first user is in a particular location. If the first user leaves the particular location, the object may no longer be visible to the second users. As another example and not by way of limitation, a first user may specify that an object is visible only to second users within a threshold distance from the first user. If the first user subsequently changes location, the original second users with access to the object may lose access, while a new group of second users may gain access as they come within the threshold distance of the first user.

In particular embodiments, the social-networking system 160 or assistant system 140 may have functionalities that may use, as inputs, personal or biometric information of a user for user-authentication or experience-personalization purposes. A user may opt to make use of these functionalities to enhance their experience on the online social network. As an example and not by way of limitation, a user may provide personal or biometric information to the social-networking system 160 or assistant system 140. The user's privacy settings may specify that such information may be used only for particular processes, such as authentication, and further specify that such information may not be shared with any third-party system 170 or used for other processes or applications associated with the social-networking system 160 or assistant system 140. As another example and not by way of limitation, the social-networking system 160 may provide a functionality for a user to provide voice-print recordings to the online social network. As an example and not by way of limitation, if a user wishes to utilize this function of the online social network, the user may provide a voice recording of his or her own voice to provide a status update on the online social network. The recording of the voice-input may be compared to a voice print of the user to determine what words were spoken by the user. The user's privacy setting may specify that such voice recording may be used only for voice-input purposes (e.g., to authenticate the user, to send voice messages, to improve voice recognition in order to use voice-operated features of the online social network), and further specify that such voice recording may not be shared with any third-party system 170 or used by other processes or applications associated with the social-networking system 160. As another example and not by way of limitation, the social-networking system 160 may provide a functionality for a user to provide a reference image (e.g., a facial profile, a retinal scan) to the online social network. The online social network may compare the reference image against a later-received image input (e.g., to authenticate the user, to tag the user in photos). The user's privacy setting may specify that such voice recording may be used only for a limited purpose (e.g., authentication, tagging the user in photos), and further specify that such voice recording may not be shared with any third-party system 170 or used by other processes or applications associated with the social-networking system 160.

Systems and Methods

FIG. 15 illustrates an example computer system 1500. In particular embodiments, one or more computer systems 1500 perform one or more steps of one or more methods described or illustrated herein. In particular embodiments, one or more computer systems 1500 provide functionality described or illustrated herein. In particular embodiments, software running on one or more computer systems 1500 performs one or more steps of one or more methods described or illustrated herein or provides functionality described or illustrated herein. Particular embodiments include one or more portions of one or more computer systems 1500. Herein, reference to a computer system may encompass a computing device, and vice versa, where appropriate. Moreover, reference to a computer system may encompass one or more computer systems, where appropriate.

This disclosure contemplates any suitable number of computer systems 1500. This disclosure contemplates computer system 1500 taking any suitable physical form. As example and not by way of limitation, computer system 1500 may be an embedded computer system, a system-on-chip (SOC), a single-board computer system (SBC) (such as, for example, a computer-on-module (COM) or system-on-module (SOM)), a desktop computer system, a laptop or notebook computer system, an interactive kiosk, a mainframe, a mesh of computer systems, a mobile telephone, a personal digital assistant (PDA), a server, a tablet computer system, or a combination of two or more of these. Where appropriate, computer system 1500 may include one or more computer systems 1500; be unitary or distributed; span multiple locations; span multiple machines; span multiple data centers; or reside in a cloud, which may include one or more cloud components in one or more networks. Where appropriate, one or more computer systems 1500 may perform without substantial spatial or temporal limitation one or more steps of one or more methods described or illustrated herein. As an example and not by way of limitation, one or more computer systems 1500 may perform in real time or in batch mode one or more steps of one or more methods described or illustrated herein. One or more computer systems 1500 may perform at different times or at different locations one or more steps of one or more methods described or illustrated herein, where appropriate.

In particular embodiments, computer system 1500 includes a processor 1502, memory 1504, storage 1506, an input/output (I/O) interface 1508, a communication interface 1510, and a bus 1512. Although this disclosure describes and illustrates a particular computer system having a particular number of particular components in a particular arrangement, this disclosure contemplates any suitable computer system having any suitable number of any suitable components in any suitable arrangement.

In particular embodiments, processor 1502 includes hardware for executing instructions, such as those making up a computer program. As an example and not by way of limitation, to execute instructions, processor 1502 may retrieve (or fetch) the instructions from an internal register, an internal cache, memory 1504, or storage 1506; decode and execute them; and then write one or more results to an internal register, an internal cache, memory 1504, or storage 1506. In particular embodiments, processor 1502 may include one or more internal caches for data, instructions, or addresses. This disclosure contemplates processor 1502 including any suitable number of any suitable internal caches, where appropriate. As an example and not by way of limitation, processor 1502 may include one or more instruction caches, one or more data caches, and one or more translation lookaside buffers (TLBs). Instructions in the instruction caches may be copies of instructions in memory 1504 or storage 1506, and the instruction caches may speed up retrieval of those instructions by processor 1502. Data in the data caches may be copies of data in memory 1504 or storage 1506 for instructions executing at processor 1502 to operate on; the results of previous instructions executed at processor 1502 for access by subsequent instructions executing at processor 1502 or for writing to memory 1504 or storage 1506; or other suitable data. The data caches may speed up read or write operations by processor 1502. The TLBs may speed up virtual-address translation for processor 1502. In particular embodiments, processor 1502 may include one or more internal registers for data, instructions, or addresses. This disclosure contemplates processor 1502 including any suitable number of any suitable internal registers, where appropriate. Where appropriate, processor 1502 may include one or more arithmetic logic units (ALUs); be a multi-core processor; or include one or more processors 1502. Although this disclosure describes and illustrates a particular processor, this disclosure contemplates any suitable processor.

In particular embodiments, memory 1504 includes main memory for storing instructions for processor 1502 to execute or data for processor 1502 to operate on. As an example and not by way of limitation, computer system 1500 may load instructions from storage 1506 or another source (such as, for example, another computer system 1500) to memory 1504. Processor 1502 may then load the instructions from memory 1504 to an internal register or internal cache. To execute the instructions, processor 1502 may retrieve the instructions from the internal register or internal cache and decode them. During or after execution of the instructions, processor 1502 may write one or more results (which may be intermediate or final results) to the internal register or internal cache. Processor 1502 may then write one or more of those results to memory 1504. In particular embodiments, processor 1502 executes only instructions in one or more internal registers or internal caches or in memory 1504 (as opposed to storage 1506 or elsewhere) and operates only on data in one or more internal registers or internal caches or in memory 1504 (as opposed to storage 1506 or elsewhere). One or more memory buses (which may each include an address bus and a data bus) may couple processor 1502 to memory 1504. Bus 1512 may include one or more memory buses, as described below. In particular embodiments, one or more memory management units (MMUs) reside between processor 1502 and memory 1504 and facilitate accesses to memory 1504 requested by processor 1502. In particular embodiments, memory 1504 includes random access memory (RAM). This RAM may be volatile memory, where appropriate. Where appropriate, this RAM may be dynamic RAM (DRAM) or static RAM (SRAM). Moreover, where appropriate, this RAM may be single-ported or multi-ported RAM. This disclosure contemplates any suitable RAM. Memory 1504 may include one or more memories 1504, where appropriate. Although this disclosure describes and illustrates particular memory, this disclosure contemplates any suitable memory.

In particular embodiments, storage 1506 includes mass storage for data or instructions. As an example and not by way of limitation, storage 1506 may include a hard disk drive (HDD), a floppy disk drive, flash memory, an optical disc, a magneto-optical disc, magnetic tape, or a Universal Serial Bus (USB) drive or a combination of two or more of these. Storage 1506 may include removable or non-removable (or fixed) media, where appropriate. Storage 1506 may be internal or external to computer system 1500, where appropriate. In particular embodiments, storage 1506 is non-volatile, solid-state memory. In particular embodiments, storage 1506 includes read-only memory (ROM). Where appropriate, this ROM may be mask-programmed ROM, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), electrically alterable ROM (EAROM), or flash memory or a combination of two or more of these. This disclosure contemplates mass storage 1506 taking any suitable physical form. Storage 1506 may include one or more storage control units facilitating communication between processor 1502 and storage 1506, where appropriate. Where appropriate, storage 1506 may include one or more storages 1506. Although this disclosure describes and illustrates particular storage, this disclosure contemplates any suitable storage.

In particular embodiments, I/O interface 1508 includes hardware, software, or both, providing one or more interfaces for communication between computer system 1500 and one or more I/O devices. Computer system 1500 may include one or more of these I/O devices, where appropriate. One or more of these I/O devices may enable communication between a person and computer system 1500. As an example and not by way of limitation, an I/O device may include a keyboard, keypad, microphone, monitor, mouse, printer, scanner, speaker, still camera, stylus, tablet, touch screen, trackball, video camera, another suitable I/O device or a combination of two or more of these. An I/O device may include one or more sensors. This disclosure contemplates any suitable I/O devices and any suitable I/O interfaces 1508 for them. Where appropriate, I/O interface 1508 may include one or more device or software drivers enabling processor 1502 to drive one or more of these I/O devices. I/O interface 1508 may include one or more I/O interfaces 1508, where appropriate. Although this disclosure describes and illustrates a particular I/O interface, this disclosure contemplates any suitable I/O interface.

In particular embodiments, communication interface 1510 includes hardware, software, or both providing one or more interfaces for communication (such as, for example, packet-based communication) between computer system 1500 and one or more other computer systems 1500 or one or more networks. As an example and not by way of limitation, communication interface 1510 may include a network interface controller (NIC) or network adapter for communicating with an Ethernet or other wire-based network or a wireless NIC (WNIC) or wireless adapter for communicating with a wireless network, such as a WI-FI network. This disclosure contemplates any suitable network and any suitable communication interface 1510 for it. As an example and not by way of limitation, computer system 1500 may communicate with an ad hoc network, a personal area network (PAN), a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), or one or more portions of the Internet or a combination of two or more of these. One or more portions of one or more of these networks may be wired or wireless. As an example, computer system 1500 may communicate with a wireless PAN (WPAN) (such as, for example, a BLUETOOTH WPAN), a WI-FI network, a WI-MAX network, a cellular telephone network (such as, for example, a Global System for Mobile Communications (GSM) network), or other suitable wireless network or a combination of two or more of these. Computer system 1500 may include any suitable communication interface 1510 for any of these networks, where appropriate. Communication interface 1510 may include one or more communication interfaces 1510, where appropriate. Although this disclosure describes and illustrates a particular communication interface, this disclosure contemplates any suitable communication interface.

In particular embodiments, bus 1512 includes hardware, software, or both coupling components of computer system 1500 to each other. As an example and not by way of limitation, bus 1512 may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a front-side bus (FSB), a HYPERTRANSPORT (HT) interconnect, an Industry Standard Architecture (ISA) bus, an INFINIBAND interconnect, a low-pin-count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCIe) bus, a serial advanced technology attachment (SATA) bus, a Video Electronics Standards Association local (VLB) bus, or another suitable bus or a combination of two or more of these. Bus 1512 may include one or more buses 1512, where appropriate. Although this disclosure describes and illustrates a particular bus, this disclosure contemplates any suitable bus or interconnect.

Herein, a computer-readable non-transitory storage medium or media may include one or more semiconductor-based or other integrated circuits (ICs) (such, as for example, field-programmable gate arrays (FPGAs) or application-specific ICs (ASICs)), hard disk drives (HDDs), hybrid hard drives (HHDs), optical discs, optical disc drives (ODDs), magneto-optical discs, magneto-optical drives, floppy diskettes, floppy disk drives (FDDs), magnetic tapes, solid-state drives (SSDs), RAM-drives, SECURE DIGITAL cards or drives, any other suitable computer-readable non-transitory storage media, or any suitable combination of two or more of these, where appropriate. A computer-readable non-transitory storage medium may be volatile, non-volatile, or a combination of volatile and non-volatile, where appropriate.

Miscellaneous

Herein, “or” is inclusive and not exclusive, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A or B” means “A, B, or both,” unless expressly indicated otherwise or indicated otherwise by context. Moreover, “and” is both joint and several, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A and B” means “A and B, jointly or severally,” unless expressly indicated otherwise or indicated otherwise by context.

The scope of this disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments described or illustrated herein that a person having ordinary skill in the art would comprehend. The scope of this disclosure is not limited to the example embodiments described or illustrated herein. Moreover, although this disclosure describes and illustrates respective embodiments herein as including particular components, elements, feature, functions, operations, or steps, any of these embodiments may include any combination or permutation of any of the components, elements, features, functions, operations, or steps described or illustrated anywhere herein that a person having ordinary skill in the art would comprehend. Furthermore, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative. Additionally, although this disclosure describes or illustrates particular embodiments as providing particular advantages, particular embodiments may provide none, some, or all of these advantages. 

What is claimed is:
 1. A method comprising, by a first client system associated with a first user: initiating, via a communication network, a communication session with a second client system associated with a second user, wherein the communication session is initiated in a first modality; receiving, from the communication network, a ping to the first client system to evaluate available bandwidth on the communication network; estimating, by the first client system, an amount of bandwidth available on the communication network for use by the first client system; determining, by the first client system, the amount of bandwidth available on the communication network for use by the first client system is insufficient for the first modality; and switching, by the first client system, the communication session with the second client system to a second modality, wherein the second modality uses less bandwidth than the first modality.
 2. The method of claim 1, wherein estimating the amount of bandwidth available on the communication network for use by the first client system is based on antenna strength associated with the first client system.
 3. The method of claim 1, wherein the second client system converts the communication session to the first modality.
 4. The method of claim 1, wherein the first modality comprises video, audio, or text.
 5. The method of claim 1, wherein the communication session comprises a video clip, an audio clip, or a text string.
 6. The method of claim 1, wherein the first modality is video, and wherein the method further comprises: determining the amount of bandwidth available on the communication network for use by the first client system is sufficient for the communication session to be in audio.
 7. The method of claim 6, wherein the second modality is audio.
 8. The method of claim 1, wherein the first modality is video, and wherein the method further comprises: determining the amount of bandwidth available on the communication network for use by the first client system is insufficient for the communication session to be in audio.
 9. The method of claim 8, wherein the second modality is text.
 10. The method of claim 1, wherein the first modality is audio and the second modality is text, and wherein switching the communication session with the second client system to the second modality is based on automated speech recognition by an audio speech recognition (ASR) module.
 11. The method of claim 10, further comprising: identifying one or more sounds associated with the audio; and adding one or more descriptions of each of the one or more sounds to the text.
 12. The method of claim 1, wherein the first modality is video and the second modality is audio, and wherein switching the communication session with the second client system to the second modality comprises: identifying one or more vocalizations associated with the video; and generating the audio based on the one or more vocalizations.
 13. The method of claim 12, further comprising: identifying one or more gestures associated with the video; generating an audio representation of the one or more gestures; and adding the audio representation to the generated audio.
 14. The method of claim 1, wherein the first modality is video and the second modality is text, and wherein switching the communication session with the second client system to the second modality comprises: identifying one or more vocalizations associated with the video; and generating the text based on the one or more vocalizations by an audio speech recognition (ASR) module.
 15. The method of claim 14, further comprising: identifying one or more gestures associated with the video; generating one or more descriptions for each of the one or more gestures; and adding the generated descriptions to the text.
 16. The method of claim 1, wherein the communication session is associated with a network interface that communicates with the communication network, and wherein the amount of bandwidth available is estimated based on one or more attributes of the network interface.
 17. The method of claim 1, wherein estimating the amount of bandwidth available comprises: receiving, at the first client system, a predetermined quantity of data via the communication network; and measuring a rate at which the predetermined quantity of data is received.
 18. One or more computer-readable non-transitory storage media embodying software that is operable when executed to: initiate, via a communication network, a communication session with a second client system associated with a second user, wherein the communication session is initiated in a first modality; receive, from the communication network, a ping to the first client system to evaluate available bandwidth on the communication network; estimate, by the first client system, an amount of bandwidth available on the communication network for use by the first client system; determine by the first client system, the amount of bandwidth available on the communication network for use by the first client system is insufficient for the first modality; and switch, by the first client system, the communication session with the second client system to a second modality, wherein the second modality uses less bandwidth than the first modality.
 19. A system comprising: one or more processors; and a non-transitory memory coupled to the processors comprising instructions executable by the processors, the processors operable when executing the instructions to: initiate, via a communication network, a communication session with a second client system associated with a second user, wherein the communication session is initiated in a first modality; receive, from the communication network, a ping to the first client system to evaluate available bandwidth on the communication network; estimate, by the first client system, an amount of bandwidth available on the communication network for use by the first client system; determine by the first client system, the amount of bandwidth available on the communication network for use by the first client system is insufficient for the first modality; and switch, by the first client system, the communication session with the second client system to a second modality, wherein the second modality uses less bandwidth than the first modality. 